Table within longtable environment in LaTeX

Question

I have a fairly long table which should go over 2 pages. I used the package longtable to be able to add \pagebreaks. Now, I used another tabular environment in one of the columns since I have a pretty long text and I want it to go over two lines. I compiled the table already, without longtable. It works perfectly. But I now I get a lot of error messages, most of them something like "misplaced alignment tab character ...". Is there another package I could that would allow me to have a table within the other (since I guess that that is the problem) or is there another way to get the text within a column to go over two lines? I am new to LaTeX and just couldn't figure it out. I also hope my MWE works, I have no idea how to get it into code.

\documentclass[12pt,a4paper]{scrreprt}
\usepackage[left=2.5cm,right=2.5cm,top=2.5cm,bottom=2cm,includeheadfoot]{geometry} 
\setlength{\headheight}{15pt}
\usepackage[labelfont=bf,textfont={small}]{caption}
\usepackage{subcaption}
\usepackage{tabularx}
\usepackage{longtable}
\usepackage{multirow}
\usepackage{booktabs}

\begin{document}
\begin{lontable}{ccccc}
    \toprule
    \textbf{Cell Line} &       & \textbf{Sub Clones} & \textbf{Name} & \textbf{Time Point} \\
    \midrule
    \endhead
    \multirow{38}[0]{*}{\textbf{CHO-K1 CTG\_S4 T}} & \multirow{23}[0]{*}{PXP} & \multirow{5}[0]{*}{\begin{tabular}{@{}c@{}}CHO-K1 CTG\_S4 \\ PXP\_S1 2B3 SVC \end{tabular}}& \multirow{5}[0]{*}{SVC3} & T\textsubscript{0} \\
    &       &       &       & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{3-5} 
    &       & \multirow{5}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\ PXP\_S2 2.3 SVC\end{tabularx}} & \multirow{5}[0]{*}{SVC5} & T\textsubscript{0} \\
    &       &       &       & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{3-5}
    &       & \multirow{4}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\ PXP\_S1 2B3 AAA\end{tabularx}} & \multirow{4}[0]{*}{AAA3} & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{3-5}
    &       & \multirow{5}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\PXP\_S1 2.1 AAA\end{tabularx}} & \multirow{5}[0]{*}{AAA4} & T\textsubscript{0} \\
    &       &       &       & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{3-5}
    &       & \multirow{4}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\PXP\_S1 2.3 AAA\end{tabularx}} & \multirow{4}[0]{*}{AAA5} & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{2-5}
    \pagebreak
    & \multirow{5}[0]{*}{PX} & \multirow{5}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\PX\_S1 3A1\end{tabularx}} & \multirow{5}[0]{*}{VD2} & T\textsubscript{0} \\
    &       &       &       & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{2-5}
    & \multirow{10}[0]{*}{TT} & \multirow{5}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\TT\_S1 1A4\end{tabularx}} & \multirow{5}[0]{*}{VD3} & T\textsubscript{0} \\
    &       &       &       & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \cmidrule{3-5}
    &       & \multirow{5}[0]{*}{\begin{tabularx}{@{}c@{}}CHO-K1 CTG\_S4 \\TT\_S1 3A4\end{tabularx}} & \multirow{5}[0]{*}{VD4} & T\textsubscript{0} \\
    &       &       &       & T\textsubscript{1} \\
    &       &       &       & T\textsubscript{2} \\
    &       &       &       & T\textsubscript{3} \\
    &       &       &       & T\textsubscript{4} \\
    \bottomrule
    \caption{Sample Table CHO-K1 CTG\_S4 T}
    \label{tab:table3}%
\end{lontable}%

\end{document}

Answer 1

Environment tabularx is wrong in two ways:

• The table width argument is missing.
• A column specifier X is missing.

Solution:

• tabularx should be replaced by tabular.
• Also, lontable needs to be replaced by longtable, because the former environment is undefined.

Answer 2

Some improvements and simplifications, using makecell in the place of a nested tabular:

\documentclass[12pt, a4paper]{scrreprt}
\usepackage[left=2.5cm,right=2.5cm,top=2.5cm,bottom=2cm,includeheadfoot, showframe]{geometry}
\setlength{\headheight}{15pt}
\usepackage[labelfont=bf, textfont={small}]{caption}
\usepackage{subcaption}
\usepackage{tabularx, makecell}
\usepackage{longtable}
\usepackage{multirow}
\usepackage{booktabs}
\renewcommand\theadfont{\normalsize\bfseries}

\begin{document}
\begin{longtable}{ccccc}
   \caption{Sample Table CHO-K1 CTG\_S4 T}
    \label{tab:table3}\\%
\addlinespace
    \toprule
    \thead{Cell Line} & & \thead{Sub Clones} & \thead{Name} & \thead{Time\\ Point} \\
    \midrule
    \endfirsthead
  \multicolumn{5}{c}{\small \tablename~\thetable\enspace (continued)}\\
\addlinespace
    \toprule
    \thead{Cell Line} & & \thead{Sub Clones} & \thead{Name} & \thead{Time\\ Point} \\
    \midrule
    \endhead
\multicolumn{5}{r}{\footnotesize To be continued}
\endfoot
\bottomrule
\endlastfoot
     & \multirow{23}[0]{*}{PXP} & \multirow{5}[0]{*}{\begin{tabular}{@{}c@{}}CHO-K1 CTG\_S4 \\ PXP\_S1 2B3 SVC \end{tabular}}& \multirow{5}[0]{*}{SVC3} & T\textsubscript{0} \\
    & & & & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{3-5}
    & & \multirow{5}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\ PXP\_S2 2.3 SVC}} & \multirow{5}[0]{*}{SVC5} & T\textsubscript{0} \\
    & & & & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{3-5}
    & & \multirow{4}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\ PXP\_S1 2B3 AAA}} & \multirow{4}[0]{*}{AAA3} & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{3-5}
    & & \multirow{5}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\PXP\_S1 2.1 AAA}} & \multirow{5}[0]{*}{AAA4} & T\textsubscript{0} \\
    & & & & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
 \textbf{CHO-K1 CTG\_S4 T} & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{3-5}
    & & \multirow{4}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\PXP\_S1 2.3 AAA}} & \multirow{4}[0]{*}{AAA5} & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{2-5}
    %\pagebreak
    & \multirow{5}[0]{*}{PX} & \multirow{5}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\PX\_S1 3A1}} & \multirow{5}[0]{*}{VD2} & T\textsubscript{0} \\
    & & & & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{2-5}
  \pagebreak
    & \multirow{10}[0]{*}{TT} & \multirow{5}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\TT\_S1 1A4}} & \multirow{5}[0]{*}{VD3} & T\textsubscript{0} \\
    & & & & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4} \\
    \cmidrule{3-5}
    & & \multirow{5}[0]{*}{\makecell{CHO-K1 CTG\_S4 \\TT\_S1 3A4}} & \multirow{5}[0]{*}{VD4} & T\textsubscript{0} \\
    & & & & T\textsubscript{1} \\
    & & & & T\textsubscript{2} \\
    & & & & T\textsubscript{3} \\
    & & & & T\textsubscript{4}
 \end{longtable}%

\end{document}