overleaf table size length of text
% Makes table with = text width
documentclass{article}
usepackage{graphicx}
begin{document}
noindenthrulefill
smallskipnoindent
resizebox{linewidth}{!}{%
begin{tabular}{r|lll}
multicolumn{1}{r}{}
& multicolumn{1}{l}{Heading 1}
& multicolumn{1}{l}{Heading 2}
& multicolumn{1}{l}{Heading 3} \ cline{2-4}
Row 1 & Cell 1,1 & Cell 1,2 & Cell 1,3 \
Row 2 & Cell 2,1 & Cell 2,2 & Cell 2,3
end{tabular}}
end{document}