
I managed to break my extra wide table using the hints provided here:
Column-wise break of extra wide tables.
As one can see, there are a lot of empty cells in the second part of the table. So I do not want to display those empty rows in the second part. Any ideas on how I could solve the problem?
\documentclass[a4paper]{article}
\usepackage{tabularx}
\usepackage{array}
\def\widesplit#1{%
\clearpage
\def\row##1##2{##1}%
#1%
\def\row##1##2{##2}%
#1%
}
\begin{document}
\widesplit{%
\begin{tabularx}{\textwidth}{l*{13}{c}}
\hline
&\multicolumn{11}{c}{} \\
\row
{ & A& B& C& D& E& F& G}{& H& I& J& K}\\
\hline
A
\row
{ & 1& & & & & & }{ & & & & } \\
B
\row
{ & 0.779& 1& & & & & }{ & & & & } \\
C
\row
{ & 0.511& 0.384& 1& & & & }{ & & & & } \\
D
\row
{ & 0.327& 0.310& 0.618& 1& & & }{ & & & & } \\
E
\row
{ & 0.0722& 0.0938& 0.157& 0.259& 1& & }{ & & & & } \\
F
\row
{ & 0.0108& 0.0141& -0.0342& 0.117& 0.0654& 1& }{ & & & & } \\
G
\row
{ & 0.429& 0.339& 0.535& 0.233& 0.0932& -0.0283& 1}{& & & & } \\
H
\row
{ & -0.404& -0.355& -0.314& -0.267& 0.0820& -0.0418& -0.201}{& 1& & & } \\
I
\row
{ & -0.0834& -0.0971& -0.319& -0.212& -0.0749& 0.0505& -0.124}{& 0.0476& 1& & } \\
J
\row
{& -0.802& -0.553& -0.681& -0.335& 0.138& 0.0799& -0.342}{& 0.434& 0.191& 1& } \\
K
\row
{& 0.786& 0.602& 0.575& 0.287& -0.00758& -0.0450& 0.336}{& -0.400& -0.169& -0.933& 1}\\
\hline
\end{tabularx}
}
\end{document}

\\to inside (both) of the{}groups but use{}for the empty ones so:{ & A& B& C& D& E& F& G\\}{& H& I& J& K\\}but{ & 0.779& 1& & & & & \\ }{}– David Carlisle May 11 '18 at 16:00