\documentclass[a4paper,12pt]{report}
 
\usepackage{
  rotating,
  multirow
}
  
\begin{document}
 
\begin{table}
\begin{center}
\begin{tabular}{|c|c|c|c|}
 
\hline
   &     & \multicolumn{2}{c|}{Symmetry} \\
\hline
   &     &  Yes &    No                  \\
\hline
\multirow{2}*{\rotatebox{90}{Split}}
   & Yes &  138 &  2719                  \\
   &  No & 5003 & 12290                  \\
\hline
                                                                                
\end{tabular}
\end{center}
\caption[Overview of Assemblies in the MSD]
{
bleah
}
\label{msdOverview}
\end{table}
 
\end{document}