I have the following table:
It is very wide. How can I reduce its width?
\begin{table}[H]
\centering
\sisetup{table-format=1.3e-2, table-alignment=center, tight-spacing}
\setlength{\tabcolsep}{3pt}
\small
\centering
\begin{tabularx}{\linewidth}{X cSS[table-format=1.5] SS[table-format=1.5]}
\toprule
ID & {ABC Dataset Name} & {$X^2$ (XXX)} & {$Y^2$ (YYYY)} \\ [0.5ex]
\midrule
DS1 & ABCDE ABCD & 0.0243 & 0.2039 \\
DS2 & ABCD & 0.0594 & 0.0015 \\
DS3 & XYZE & 0.2318 & 0.7709 \\
DS4 & ABC ABC & 0.1555 & 0.5613 \\ [1ex]
\bottomrule
\end{tabularx}
\caption{11 my caption}
\label{table:3}
\end{table}

\begin{tabularx}{0.6\linewidth}perhaps, depending on the content.... that is what the 1st argument of thetabularxenvironment is meant for: Specification of table width, from which the space for theXcolumns is calculated. Please don't post such fragments only. Using\centeringin a\linewidthwide table is also pretty useless – Jan 01 '18 at 08:08