alignment issue with sidewaystable enviroment in LaTeX

Question

I am having an alignment issue with the entries that I am entering in my table. I use inform3 class and the output looks like

Here are two important things: i) when I use . in any of the entry, it messes up the entire table as shown here. ii) When I use math mode, it changes the numbers. For instance, if I use $67.1$, it shows me 80 for some reason.

\begin{sidewaystable}  
\vspace*{20\baselineskip}
\setcellgapes{0pt}  
\makegapedcells       
\setlength\tabcolsep{2pt}   
\sisetup{group-four-digits}  
  \centering
  \caption{My Table}
  \small                     
    \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}} l  
                                *{2}{S[table-format=5.0]}  
                                *{16}{S[table-format=6.0]} } 
     \toprule[\heavyrulewidth] 
       &        & \multicolumn{4}{l}{{[}1{]}}    & \multicolumn{4}{l}{{[}2{]}}           & \multicolumn{4}{l}{{[}3{]}}         & \multicolumn{4}{l}{{[}4{]}}     \\
    \cmidrule[\heavyrulewidth](lr){3-6}   \cmidrule[\heavyrulewidth](lr){7-10} \cmidrule[\heavyrulewidth](lr){11-14} \cmidrule[\heavyrulewidth]{15-18}   % <--- changed
$\mathbf{|V|}$ & $\mathbf{|m|}$ & \textbf{Status} & \textbf{\begin{tabular}[c]{@{}l@{}}Time\\ (sec)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}Gap\\ ($\%$)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}BB\\ Nodes\end{tabular}} & \textbf{Status} & \textbf{\begin{tabular}[c]{@{}l@{}}Time\\ (sec)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}Gap\\ ($\%$)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}BB\\ Nodes\end{tabular}} & \textbf{Status} & \textbf{\begin{tabular}[c]{@{}l@{}}Time\\ (sec)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}Gap\\ ($\%$)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}BB\\ Nodes\end{tabular}} & \textbf{Status} & \textbf{\begin{tabular}[c]{@{}l@{}}Time\\ (sec)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}Gap\\ ($\%$)\end{tabular}} & \textbf{\begin{tabular}[c]{@{}l@{}}BB\\ Nodes\end{tabular}} \\
    \midrule
500  & 10  & {status1}  & 67.1   & 0.00  & 9639     & {status1}     & 25.3  & 0.00  & 2301  & {status2} & 66.9   & 0.00 & 1335     & {status2}     & 201.3  & 0.00 & 1479  \\
    \bottomrule     
    \end{tabular*}  
  \label{table1}
\end{sidewaystable}

Answer 1

• Please always provide MWE (Minimal Working Example, a small complete document, which we can compile as it is and which reproduce your problem).
• From one row of table we can't know, if numbers in the other rows are bigger as they are in showed row.
• Please show image of table in question, link can become dead after while.
• From provided code can be concluded, that table consist (after first two columns) four groups of data, from which in the first column are text, other three have numbers with different number of integer and decimal digits. This should be reflected in table's columns specification (see MWE below).
• For column header you can use makecell macro from the package with the same name. Using it the code will become much shorter and clearer.

\documentclass{article}% i still haven't inform3 document class
\usepackage{rotating}
\usepackage{booktabs, makecell}
\usepackage{siunitx}

\usepackage{mathtools}                      % new
\DeclarePairedDelimiter\abs{\lvert}{\rvert} % new
\usepackage{bm}                             % new


\begin{document}
    \begin{sidewaystable}
%\vspace*{20\baselineskip}
\setlength\tabcolsep{0pt}
\sisetup{group-four-digits}
\renewcommand{\cellset}{\bfseries\linespread{0.84}\selectfont}
\renewcommand\cellalign{bc}
  \centering
  \caption{My Table}
  \small
    \begin{tabular*}{\linewidth}{@{\extracolsep{\fill}} 
                        *{2}{S[table-format=3.0]}
                        *{4}{l S[table-format=2.1] S[table-format=1.2] S[table-format=4.0]}
                                }
     \toprule
    &   & \multicolumn{4}{c}{[1]}   & \multicolumn{4}{c}{[2]}           
        & \multicolumn{4}{c}{[3]}   & \multicolumn{4}{c}{[4]}   \\
    \cmidrule(l){3-6}\cmidrule(l){7-10}\cmidrule(l){11-14}\cmidrule(l){15-18}
{$\bf\abs{V}$} 
    & {$\bf\abs{m}$}            & \makecell{Status}         & {\makecell{Time\\ (sec)}} 
    & {\makecell{Gap\\ ($\%$)}} & {\makecell{BB\\ Nodes}}   & {\makecell{Status}} 
    & {\makecell{Time\\ (sec)}} & {\makecell{Gap\\ ($\%$)}} & {\makecell{BB\\ Nodes}} 
    & {\makecell{Status}}       & {\makecell{Time\\ (sec)}} & {\makecell{Gap\\ ($\%$)}} 
    & {\makecell{BB\\ Nodes}}   & {\makecell{Status}}       & {\makecell{Time\\ (sec)}} 
    & {\makecell{Gap\\ ($\%$)}} & {\makecell{BB\\ Nodes}}       \\
    \midrule
500 & 10  
    & status1   & 67.1  & 0.00  & 9639     
    & status1   & 25.3  & 0.00  & 2301  
    & status2   & 66.9  & 0.00  & 1335     
    & status2   & 201.3 & 0.00  & 1479  \\
    \bottomrule
    \end{tabular*}
  \label{table1}
\end{sidewaystable}
\end{document}