Table exceeding one page

Question

I have used the following code to fit a multi column table using landscape package. Now the data inserted is exceeding the length of the page and hence the data is not fitting. (the width is fitting fine)

I tried using the \longtable environment but it just bunches all the columns together. I tried using \tiny option but the same result.

I have seen other posts on many latex pages but haven't found a satisfactory answer that works.

MWE of my code is here

\documentclass[twoside,12pt]{book}%{Latex/   Classes/PhDthesisPSnPDF}
\usepackage[vmargin=25mm]{geometry}
\usepackage{pdflscape}
\usepackage{booktabs, makecell}



\begin{document}
\begin{landscape}
\begin{table}[ht]
\footnotesize
    \centering
    \caption{\textbf{Global parameters of low redshift AGN (z $<$ 1.0).} }
    \label{LowRS}
\setlength\tabcolsep{0pt}
    \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}} cccccccccc }
        \toprule
        Spectrum No.   &   $\lambda_{o}$ / Line  
        &   \makecell{  F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (min)} 
        &  \makecell{   F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (max)} 
        &  \makecell{   F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (avg)} & EW
        &   \makecell{  R$_{max}$   \\ $\pm/ \Delta$    R$_{max}$ }  
        &   \makecell{  F$_{var}$   \\ $\pm/ \Delta$    F$_{var}$ }  
        & \makecell{$\Delta$ T \\ (days)}  
        &  N         \\  
        \midrule
        %% table body

&       &               &   1981    &               &               &       &               &       &       \\      
S15456  &   Si IV   &   1.99    $\pm$   0.1 &   SWP11310    &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

SWP15456    &   CIV &   6.13    $\pm$   0.1 &   SWP11310    &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1982    &               &               &       &               &       &       \\                                  

S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1983 &              &               &       &               &       &       \\                                  


S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1984    &               &               &       &               &       &       \\                                  


S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1988    &               &               &       &               &       &       \\                                  


S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1989    &               &               &       &               &       &       \\                                  


S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1990 &              &               &       &               &       &       \\                                  


S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  

&       &               &   1995    &               &               &       &               &       &       \\                                  


S15456  &   Si IV   &   1.99    $\pm$   0.1 &   S11310  &   1.53    $\pm$   0.08    &   1.76    $\pm$   0.09    &   19.24   &   1.3 $\pm$   0.09    &   266.916 &   3   \\                                  

S15456  &   CIV &   6.13    $\pm$   0.1 &   S11310  &   6.41    $\pm$   0.06    &   6.27    $\pm$   0.08    &   73.39   &   1.05    $\pm$   0.02    &   266.916 &   3   \\                                  

L11470  &   CIII]   &   1.85    $\pm$   0.07    &   L11470  &   6.38    $\pm$   0.06    &   4.12    $\pm$   0.07    &   40.66   &   5.26    $\pm$   0.19    &   0   &   6   \\                                  

L11947  &   Mg II   &   0.98    $\pm$   0.05    &   L11479  &   0.79    $\pm$   0.05    &   0.89    $\pm$   0.05    &   16.42   &   1.45    $\pm$   0.12    &   63.481  &   3   \\                                  

L9917   &   2475    &   4.95    $\pm$   0.02    &   L11947  &   6.08    $\pm$   0.02    &   5.52    $\pm$   0.02    &   -   &   1.355151515 $\pm$   0.007   &   266.98608   &   4   \\                                  

L9917   &   2625    &   4.59    $\pm$   0.02    &   L11947  &   5.19    $\pm$   0.02    &   4.89    $\pm$   0.02    &   -   &   1.331881533 $\pm$   0.008   &   266.98608   &   4   \\                                  

L9917   &   2687.5  &   4.43    $\pm$   0.04    &   L11947  &   4.88    $\pm$   0.04    &   4.66    $\pm$   0.04    &   -   &   1.449232852 $\pm$   0.018   &   266.98608   &   4   \\                                  

L9917   &   2875    &   4.19    $\pm$   0.02    &   L11947  &   4.6 $\pm$   0.02    &   4.4 $\pm$   0.02    &   -   &   1.370379203 $\pm$   0.009   &   266.98608   &   4   \\                                  
                            


            \bottomrule
        \end{tabular*}
        \end{table}
    \end{landscape}
    \end{document}

Answer 1

Try:

\documentclass[twoside,12pt]{book}%{Latex/   Classes/PhDthesisPSnPDF}
\usepackage[vmargin=25mm]{geometry}
\usepackage{pdflscape}
\usepackage{booktabs, longtable, makecell}

\begin{document}
\begin{landscape}
\setlength{\LTleft}{0pt}
\setlength{\LTright}{0pt}
\setlength\LTcapwidth{\linewidth}
\setlength\tabcolsep{0pt}
    \begin{longtable}{@{\extracolsep{\fill}} cc cc cc cc cc }
    \caption{\textbf{Global parameters of low redshift AGN (z $<$ 1.0).} }
    \label{LowRS}   \\
        \toprule
        Spectrum No.   &   $\lambda_{o}$ / Line
        &   \makecell{F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (min)}
        &   \makecell{F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (max)}
        &   \makecell{F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (avg)} 
        & EW
        &   \makecell{R$_{max}$   \\ $\pm/ \Delta$    R$_{max}$ }
        &   \makecell{F$_{var}$   \\ $\pm/ \Delta$    F$_{var}$ }
        &   \makecell{$\Delta$ T \\ (days)}
        &  N         \\
        \midrule
\endfirsthead        
    \caption[]{\textbf{Global parameters of low redshift AGN (z $<$ 1.0).} }\\
        \toprule
        Spectrum No.   &   $\lambda_{o}$ / Line
        &   \makecell{F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (min)}
        &   \makecell{F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (max)}
        &   \makecell{F$_\lambda$ $\pm/ \Delta$   F$_\lambda$ \\ (avg)}
        & EW
        &   \makecell{R$_{max}$   \\ $\pm/ \Delta$    R$_{max}$ }
        &   \makecell{F$_{var}$   \\ $\pm/ \Delta$    F$_{var}$ }
        &   \makecell{$\Delta$ T \\ (days)}
        &  N         \\
        \midrule
\endhead   
    \midrule     
    \multicolumn{10}{r}{\small\textit{Continue on the next page}}
\endfoot
    \bottomrule
\endlastfoot    
        %% table body
            &   &   &   1981    &   &   &   &   &   &       \\
S15456      & Si IV 
            & 1.99 $\pm$ 0.1  & SWP11310        & 1.53 $\pm$ 0.08   & 1.76 $\pm$ 0.09
            & 19.24           & 1.3 $\pm$ 0.09  & 266.916           &   3   \\
SWP15456    & CIV
            & 6.13 $\pm$ 0.1  & SWP11310        & 6.41 $\pm$ 0.06   & 6.27 $\pm$ 0.08
            & 73.39           & 1.05 $\pm$ 0.02 & 266.916           &   3   \\
L11470      & CIII]
            & 1.85 $\pm$ 0.07 & L11470          & 6.38 $\pm$ 0.06   & 4.12 $\pm$ 0.07 
            & 40.66           & 5.26 $\pm$ 0.19 & 0                 &   6   \\
L11947      & Mg II   
            & 0.98 $\pm$ 0.05 & L11479          & 0.79 $\pm$ 0.05   & 0.89 $\pm$ 0.05
            & 16.42           & 1.45 $\pm$ 0.12 & 63.481            &   3   \\
L9917       & 2475    
            & 4.95 $\pm$ 0.02 & L11947          & 6.08 $\pm$ 0.02   & 5.52 $\pm$ 0.02
            &   -             & 1.355151515 $\pm$ 0.007 & 266.98608 &   4   \\
L9917       & 2625    
            & 4.59 $\pm$ 0.02 &   L11947        & 5.19 $\pm$ 0.02   & 4.89 $\pm$ 0.02
            &   -             & 1.331881533 $\pm$ 0.008 & 266.98608 &   4   \\
L9917       & 2687.5  
            & 4.43 $\pm$ 0.04 & L11947          & 4.88 $\pm$ 0.04   & 4.66 $\pm$ 0.04   
            &   -             & 1.449232852 $\pm$ 0.018 & 266.98608 &   4   \\
L9917       & 2875    
            & 4.19 $\pm$ 0.02 & L11947          & 4.6 $\pm$ 0.02    & 4.4 $\pm$ 0.02    
            &   -             & 1.370379203 $\pm$ 0.009 & 266.98608 &   4   \\
            
            &   &   &   1982    &   &   &   &   &   &       \\
S15456      & Si IV
            & 1.99 $\pm$ 0.1  & SWP11310        & 1.53 $\pm$ 0.08   & 1.76 $\pm$ 0.09
            & 19.24           & 1.3 $\pm$ 0.09  & 266.916           &   3   \\
SWP15456    & CIV
            & 6.13 $\pm$ 0.1  & SWP11310        & 6.41 $\pm$ 0.06   & 6.27 $\pm$ 0.08
            & 73.39           & 1.05 $\pm$ 0.02 & 266.916           &   3   \\
L11470      & CIII]
            & 1.85 $\pm$ 0.07 & L11470          & 6.38 $\pm$ 0.06   & 4.12 $\pm$ 0.07
            & 40.66           & 5.26 $\pm$ 0.19 & 0                 &   6   \\
L11947      & Mg II
            & 0.98 $\pm$ 0.05 & L11479          & 0.79 $\pm$ 0.05   & 0.89 $\pm$ 0.05
            & 16.42           & 1.45 $\pm$ 0.12 & 63.481            &   3   \\
L9917       & 2475
            & 4.95 $\pm$ 0.02 & L11947          & 6.08 $\pm$ 0.02   & 5.52 $\pm$ 0.02
            &   -             & 1.355151515 $\pm$ 0.007 & 266.98608 &   4   \\
L9917       & 2625
            & 4.59 $\pm$ 0.02 &   L11947        & 5.19 $\pm$ 0.02   & 4.89 $\pm$ 0.02
            &   -             & 1.331881533 $\pm$ 0.008 & 266.98608 &   4   \\
L9917       & 2687.5
            & 4.43 $\pm$ 0.04 & L11947          & 4.88 $\pm$ 0.04   & 4.66 $\pm$ 0.04
            &   -             & 1.449232852 $\pm$ 0.018 & 266.98608 &   4   \\
L9917       & 2875
            & 4.19 $\pm$ 0.02 & L11947          & 4.6 $\pm$ 0.02    & 4.4 $\pm$ 0.02
            &   -             & 1.370379203 $\pm$ 0.009 & 266.98608 &   4   \\

            &   &   &   1983    &   &   &   &   &   &       \\
S15456      & Si IV
            & 1.99 $\pm$ 0.1  & SWP11310        & 1.53 $\pm$ 0.08   & 1.76 $\pm$ 0.09
            & 19.24           & 1.3 $\pm$ 0.09  & 266.916           &   3   \\
SWP15456    & CIV
            & 6.13 $\pm$ 0.1  & SWP11310        & 6.41 $\pm$ 0.06   & 6.27 $\pm$ 0.08
            & 73.39           & 1.05 $\pm$ 0.02 & 266.916           &   3   \\
L11470      & CIII]
            & 1.85 $\pm$ 0.07 & L11470          & 6.38 $\pm$ 0.06   & 4.12 $\pm$ 0.07
            & 40.66           & 5.26 $\pm$ 0.19 & 0                 &   6   \\
L11947      & Mg II
            & 0.98 $\pm$ 0.05 & L11479          & 0.79 $\pm$ 0.05   & 0.89 $\pm$ 0.05
            & 16.42           & 1.45 $\pm$ 0.12 & 63.481            &   3   \\
L9917       & 2475
            & 4.95 $\pm$ 0.02 & L11947          & 6.08 $\pm$ 0.02   & 5.52 $\pm$ 0.02
            &   -             & 1.355151515 $\pm$ 0.007 & 266.98608 &   4   \\
L9917       & 2625
            & 4.59 $\pm$ 0.02 &   L11947        & 5.19 $\pm$ 0.02   & 4.89 $\pm$ 0.02
            &   -             & 1.331881533 $\pm$ 0.008 & 266.98608 &   4   \\
L9917       & 2687.5
            & 4.43 $\pm$ 0.04 & L11947          & 4.88 $\pm$ 0.04   & 4.66 $\pm$ 0.04
            &   -             & 1.449232852 $\pm$ 0.018 & 266.98608 &   4   \\
L9917       & 2875
            & 4.19 $\pm$ 0.02 & L11947          & 4.6 $\pm$ 0.02    & 4.4 $\pm$ 0.02
            &   -             & 1.370379203 $\pm$ 0.009 & 266.98608 &   4   \\
            
            &   &   &   1983    &   &   &   &   &   &       \\
S15456      & Si IV
            & 1.99 $\pm$ 0.1  & SWP11310        & 1.53 $\pm$ 0.08   & 1.76 $\pm$ 0.09
            & 19.24           & 1.3 $\pm$ 0.09  & 266.916           &   3   \\
SWP15456    & CIV
            & 6.13 $\pm$ 0.1  & SWP11310        & 6.41 $\pm$ 0.06   & 6.27 $\pm$ 0.08
            & 73.39           & 1.05 $\pm$ 0.02 & 266.916           &   3   \\
L11470      & CIII]
            & 1.85 $\pm$ 0.07 & L11470          & 6.38 $\pm$ 0.06   & 4.12$\pm$ 0.07
            & 40.66           & 5.26 $\pm$ 0.19 & 0                 &   6   \\
L11947      & Mg II
            & 0.98 $\pm$ 0.05 & L11479          & 0.79 $\pm$ 0.05   & 0.89 $\pm$ 0.05
            & 16.42           & 1.45 $\pm$ 0.12 & 63.481            &   3   \\
L9917       & 2475
            & 4.95 $\pm$ 0.02 & L11947          & 6.08 $\pm$ 0.02   & 5.52 $\pm$ 0.02
            &   -             & 1.355151515 $\pm$ 0.007 & 266.98608 &   4   \\
L9917       & 2625
            & 4.59 $\pm$ 0.02 &   L11947        & 5.19 $\pm$ 0.02   & 4.89 $\pm$ 0.02
            &   -             & 1.331881533 $\pm$ 0.008 & 266.98608 &   4   \\
L9917       & 2687.5
            & 4.43 $\pm$ 0.04 & L11947          & 4.88 $\pm$ 0.04   & 4.66 $\pm$ 0.04
            &   -             & 1.449232852 $\pm$ 0.018 & 266.98608 &   4   \\
L9917       & 2875
            & 4.19 $\pm$ 0.02 & L11947          & 4.6 $\pm$ 0.02    & 4.4 $\pm$ 0.02
            &   -             & 1.370379203 $\pm$ 0.009 & 266.98608 &   4   \\

            &   &   &   1984    &   &   &   &   &   &       \\
S15456      & Si IV
            & 1.99 $\pm$ 0.1  & SWP11310        & 1.53 $\pm$ 0.08   & 1.76 $\pm$ 0.09
            & 19.24           & 1.3 $\pm$ 0.09  & 266.916           &   3   \\
SWP15456    & CIV
            & 6.13 $\pm$ 0.1  & SWP11310        & 6.41 $\pm$ 0.06   & 6.27 $\pm$ 0.08
            & 73.39           & 1.05 $\pm$ 0.02 & 266.916           &   3   \\
L11470      & CIII]
            & 1.85 $\pm$ 0.07 & L11470          & 6.38 $\pm$ 0.06   & 4.12$\pm$ 0.07
            & 40.66           & 5.26 $\pm$ 0.19 & 0                 &   6   \\
L11947      & Mg II
            & 0.98 $\pm$ 0.05 & L11479          & 0.79 $\pm$ 0.05   & 0.89 $\pm$ 0.05
            & 16.42           & 1.45 $\pm$ 0.12 & 63.481            &   3   \\
L9917       & 2475
            & 4.95 $\pm$ 0.02 & L11947          & 6.08 $\pm$ 0.02   & 5.52 $\pm$ 0.02
            &   -             & 1.355151515 $\pm$ 0.007 & 266.98608 &   4   \\
L9917       & 2625
            & 4.59 $\pm$ 0.02 &   L11947        & 5.19 $\pm$ 0.02   & 4.89 $\pm$ 0.02
            &   -             & 1.331881533 $\pm$ 0.008 & 266.98608 &   4   \\
L9917       & 2687.5
            & 4.43 $\pm$ 0.04 & L11947          & 4.88 $\pm$ 0.04   & 4.66 $\pm$ 0.04
            &   -             & 1.449232852 $\pm$ 0.018 & 266.98608 &   4   \\
L9917       & 2875
            & 4.19 $\pm$ 0.02 & L11947          & 4.6 $\pm$ 0.02    & 4.4 $\pm$ 0.02
            &   -             & 1.370379203 $\pm$ 0.009 & 266.98608 &   4   \\

            &   &   &   1985    &   &   &   &   &   &       \\
S15456      & Si IV
            & 1.99 $\pm$ 0.1  & SWP11310        & 1.53 $\pm$ 0.08   & 1.76 $\pm$ 0.09
            & 19.24           & 1.3 $\pm$ 0.09  & 266.916           &   3   \\
SWP15456    & CIV
            & 6.13 $\pm$ 0.1  & SWP11310        & 6.41 $\pm$ 0.06   & 6.27 $\pm$ 0.08
            & 73.39           & 1.05 $\pm$ 0.02 & 266.916           &   3   \\
L11470      & CIII]
            & 1.85 $\pm$ 0.07 & L11470          & 6.38 $\pm$ 0.06   & 4.12$\pm$ 0.07
            & 40.66           & 5.26 $\pm$ 0.19 & 0                 &   6   \\
L11947      & Mg II
            & 0.98 $\pm$ 0.05 & L11479          & 0.79 $\pm$ 0.05   & 0.89 $\pm$ 0.05
            & 16.42           & 1.45 $\pm$ 0.12 & 63.481            &   3   \\
L9917       & 2475
            & 4.95 $\pm$ 0.02 & L11947          & 6.08 $\pm$ 0.02   & 5.52 $\pm$ 0.02
            &   -             & 1.355151515 $\pm$ 0.007 & 266.98608 &   4   \\
L9917       & 2625
            & 4.59 $\pm$ 0.02 &   L11947        & 5.19 $\pm$ 0.02   & 4.89 $\pm$ 0.02
            &   -             & 1.331881533 $\pm$ 0.008 & 266.98608 &   4   \\
L9917       & 2687.5
            & 4.43 $\pm$ 0.04 & L11947          & 4.88 $\pm$ 0.04   & 4.66 $\pm$ 0.04
            &   -             & 1.449232852 $\pm$ 0.018 & 266.98608 &   4   \\
L9917       & 2875
            & 4.19 $\pm$ 0.02 & L11947          & 4.6 $\pm$ 0.02    & 4.4 $\pm$ 0.02
            &   -             & 1.370379203 $\pm$ 0.009 & 266.98608 &   4   \\
    \end{longtable}
\end{landscape}
\end{document}

after at least two compilation you will obtain:

Addedndum:

You may liked the following redesign of your table:

\documentclass[twoside,12pt]{book}%{Latex/   Classes/PhDthesisPSnPDF}
\usepackage[vmargin=25mm]{geometry}
\usepackage{pdflscape}
\usepackage{booktabs, longtable, makecell}
\usepackage{amsmath}
\usepackage[skip=1ex, font={small,sf,bf}]{caption}
\usepackage{siunitx}

\begin{document}
\begin{landscape}
\setlength{\LTleft}{0pt}
\setlength{\LTright}{0pt}
\setlength\LTcapwidth{\linewidth}
\setlength\tabcolsep{0pt}
    \sisetup{separate-uncertainty}
    \begin{longtable}{@{\extracolsep{\fill}} 
                        ll 
                        S[table-format=1.2(3)]
                        l
                   *{2}{S[table-format=1.2(3)]}
                        S[table-format=2.2]
                        S[table-format=1.3, round-integer-to-decimal,
                          round-mode=places,
                          round-precision = 3]
                     @{\hspace{-2em}}S
                        S[table-format=3.5]
                        c}
    \caption{Global parameters of low redshift AGN (z $<$ 1.0).} 
    \label{LowRS}   \\
        \toprule
\makecell{Spectrum\\ No.}
        &  $\lambda_{o}$/ Line
        &  {\makecell{F$_\lambda\pm\Delta$F$_\lambda$ \\ (min)}}
        &  {\makecell{F$_{\lambda}\pm\Delta$F$_{\lambda}$ \\ (max)}}
        &  {\makecell{F$_{\lambda}\pm\Delta$F$_{\lambda}$ \\ (avg)}}
        &  {EW}
        &  {\makecell{R$_{\max}$\\ $\pm\Delta$R$_{\max}$}}
        &  \multicolumn{2}{c}{\makecell{F$_{var}  \pm\Delta$F$_{var}$ }}
        &  {\makecell{$\Delta$T\\ (days)}}
        &  {N}                  \\
        \midrule
\endfirsthead
    \caption[]{Global parameters of low redshift AGN (z $<$ 1.0).}\\
        \toprule
Spectrum No.
        &  $\lambda_{o}$/ Line
        &  {\makecell{F$_\lambda\pm\Delta$F$_\lambda$ \\ (min)}}
        &  {\makecell{F$_{\lambda}\pm\Delta$F$_{\lambda}$ \\ (max)}}
        &  {\makecell{F$_{\lambda}\pm\Delta$F$_{\lambda}$ \\ (avg)}}
        &  {EW}
        &  {\makecell{R$_{\max}$\\ $\pm\Delta$R$_{\max}$}}
        &  \multicolumn{2}{c}{\makecell{F$_{var}  \pm\Delta$F$_{var}$ }}
        &  {\makecell{$\Delta$T\\ (days)}}
        &  {N}                  \\
        \midrule
\endhead
    \midrule
    \multicolumn{10}{r}{\small\textit{Continue on the next page}}
\endfoot
    \bottomrule
\endlastfoot
%%%% table body
            &   &   & \textbf{1981}         &   &   &   &   &   &       \\*
S15456      & Si IV 
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09  
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV           
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08    
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII   
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II   
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05    
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475    
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625    
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5  
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875    
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02    
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1982}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1983}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1984}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1985}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1986}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1987}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1988}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & SWP11310      & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
SWP15456    & CIV
            & 6.13\pm 0.1   & SWP11310      & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII
            & 1.85\pm 0.07  & L11470        & 6.38\pm0.06   & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            & 16.42         & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm  0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1989}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & S11310        & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
S15456      & CIV
            & 6.13\pm 0.1   & S11310        & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII]
            & 1.85\pm 0.07  & L11470        & 6.38\pm 0.06  & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            &16.42          & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm 0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
%%%%
    \addlinespace
            &   &   & \textbf{1990}         &   &   &   &   &   &       \\*
S15456      & Si IV
            & 1.99\pm 0.1   & S11310        & 1.53\pm 0.08  & 1.76\pm 0.09
            & 19.24         & 1.3           &\pm 0.09   & 266.916   & 3 \\*
S15456      & CIV
            & 6.13\pm 0.1   & S11310        & 6.41\pm 0.06  & 6.27\pm 0.08
            & 73.39         & 1.05          &\pm 0.02   & 266.916   & 3 \\
L11470      & CIII]
            & 1.85\pm 0.07  & L11470        & 6.38\pm 0.06  & 4.12\pm 0.07
            & 40.66         & 5.26          &\pm 0.19   & 0         & 6 \\
L11947      & Mg II
            & 0.98\pm 0.05  & L11479        & 0.79\pm 0.05  & 0.89\pm 0.05
            &16.42          & 1.45          &\pm 0.12   & 63.481    & 3 \\
L9917       & 2475
            & 4.95\pm 0.02  & L11947        & 6.08\pm 0.02  & 5.52\pm 0.02
            & {--}          & 1.355151515   &\pm 0.007  & 266.98608 & 4 \\
L9917       & 2625
            & 4.59\pm 0.02  & L11947        & 5.19\pm 0.02  & 4.89\pm 0.02
            & {--}          & 1.331881533   &\pm 0.008  & 266.98608 & 4 \\
L9917       & 2687.5
            & 4.43\pm 0.04  & L11947        & 4.88\pm 0.04  & 4.66\pm 0.04
            & {--}          & 1.449232852   &\pm 0.018  & 266.98608 & 4 \\
L9917       & 2875
            & 4.19\pm 0.02  & L11947        & 4.6\pm 0.02   & 4.4\pm 0.02
            & {--}          & 1.370379203   &\pm 0.009  & 266.98608 & 4 \\
    \end{longtable}
\end{landscape}
\end{document}

Edit: Now table body of the second exmple is completed