i want the second "diffusivity" verticallay centered within its obvious scope
MWE
\documentclass{scrreprt}
\usepackage{amsmath}
\begin{document}
\begin{table}
\centering
\begin{tabular}{c c c c}
\hline
Variable &Region Variable &Value &Unit \\ \hline
area &$A$ &0 &m\\ \hline
&$L_{1}$ &0 &m\\
lengths &$L_{2}$ &0 &m\\
&$L_{3}$ &0 &m\\ \hline
&$D_{1}$\\
diffusivity &$D_{2}$\\
&$D_{3}$\\ \hline
diffusivity &$D_{1}$\\
&$D_{2}$\\ \hline
\end{tabular}
\caption{xyz}
\label{tab:para}
\end{table}
\end{document}
multirow
: ctan.org/pkg/multirow (BTW the package needs some improvements)