Best way to add space between columns with alternating colored rows

Question

I did some search on the topic without success. Most of the time people want to remove spaces, or have problems with last column, etc. In my case I want the spaces to be there and between columns.

I have manage to do so using a colored rule but that doesn't look good (the code I mean) and feels like kind of a workaround.

The main issue here is that my table will be printed and filled by hand, so the vertical separation must be clear and even/odd coloring is necessary to avoid confusion.

Edit: As stated by Zarko my question was not clear enough, so I'm rephrasing.

Is there a best/more elegant way of adding space between columns with alternating colored rows?

I've used rowcolors for alternating color (SpringGreen/gray) rows but other solutions might be suitable too. The space between rows isn't much important to me, as the coloring does define were each rows starts/ends.

\documentclass[landscape]{memoir}
\usepackage[table,dvipsnames]{xcolor}
\usepackage{booktabs}
\usepackage{multirow}
\newcolumntype{L}[1]{>{\raggedright\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}

\begin{document}
\arrayrulecolor{white}
\setlength{\arrayrulewidth}{3pt}
\begin{table}[ht]
\rowcolors{3}{SpringGreen}{gray!20!white}
{\large 
\centering
\label{my-label}
\begin{tabular}{>{\kern-\tabcolsep}C{2cm}|L{2cm}|L{2cm}|L{2cm}|L{2cm}|L{2cm}|L{2cm}<{\kern-\tabcolsep}}
\arrayrulecolor{black} 
\toprule
Part &  \multicolumn{5}{c}{\multirow{2}{*}{Calibration date}} \\
Number & \multicolumn{5}{c}{}   \\
\midrule
 &  &  &  &  &  &  \\ 
 &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\  
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\ 
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\
  &  &  &  &  &  &  \\  
  &  &  &  &  &  &  \\ 
\arrayrulecolor{black} 
\bottomrule
\end{tabular}
}
\end{table}
\end{document}

Answer 1

The easiest is probably to simply insert some space between the columns:

\documentclass[landscape]{memoir}
\usepackage[table,dvipsnames]{xcolor}
\usepackage{booktabs}
\usepackage{multirow}
\newcolumntype{L}[1]{>{\raggedright\let\newline\\\arraybackslash\hspace{0pt}}m{#1}!{\hspace{3pt}}}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}!{\hspace{3pt}}}

\begin{document}
\begin{table}[ht]
\rowcolors[]{3}{SpringGreen}{gray!20!white}

\begin{tabular}{C{2cm}L{2cm}L{2cm}L{2cm}L{2cm}L{2cm}L{2cm}}
\toprule
Part &  \multicolumn{5}{c}{\multirow{2}{*}{Calibration date}} \\
Number & \multicolumn{5}{c}{}   \\
\midrule
adk\hfill blbl &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\
 &  &  &  &  &  &  \\ 
\bottomrule
\end{tabular}

\end{table}
\end{document}

Answer 2

I guess that you like to obtain something like this:

To code is added makecell package for use of macro \thead{...} in column headings. Coloring of cells is moved to definition of new column type C, all rules has standard width and color. With this I estimate that code is more concise and simple:

\documentclass[landscape]{memoir}
\usepackage[table]{xcolor}
\usepackage{booktabs,makecell}
\renewcommand\theadfont{\bfseries\large}
\newcolumntype{C}{>{\color{white}\columncolor{gray!30}[.5\tabcolsep]%
                    \centering\arraybackslash}p{20mm}}
\newcommand\mc[2]{\multicolumn{#1}{c}{\thead{#2}}}

\begin{document}
\begin{table}[ht]
    \centering
    \begin{tabular}{@{$\;$} *{7}{C} @{\rule{0pt}{5ex}$\;$} }
    \toprule
\mc{1}{Part\\ Number} &  \mc{6}{Calibration date} \\
    \midrule
 &  &  &  &  &  &  \\   \addlinespace[8pt]% if you like bigger vertical space
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\
    \bottomrule
\end{tabular}
    \end{table}
\end{document}

Addendum: Instead two alternating rows' color see if increasing vertical space at each second second row. In this case the table looks as follows:

Code:

\documentclass[landscape]{memoir}
\usepackage[table]{xcolor}
\usepackage{booktabs,makecell}
\renewcommand\theadfont{\bfseries\large}
\newcolumntype{C}{>{\color{white}\columncolor{gray!30}[.5\tabcolsep]%
                    \centering\arraybackslash}p{20mm}}
\newcommand\mc[2]{\multicolumn{#1}{c}{\thead{#2}}}

\begin{document}
\begin{table}[ht]
    \centering
    \begin{tabular}{@{$\;$} C @{\qquad} *{6}{C} @{\rule{0pt}{5ex}$\;$} }
    \toprule
\mc{1}{Part\\ Number} &  \mc{6}{Calibration date} \\
    \midrule
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace[12pt]
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace[12pt]
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\   \addlinespace[12pt]
 &  &  &  &  &  &  \\   \addlinespace
 &  &  &  &  &  &  \\
    \bottomrule
\end{tabular}
    \end{table}
\end{document}