With some \multicolumn and \multirow commands as well as using arrows of specific size from here, you can achieve the desired result. For the bold column, I hvave used >{\bfseries}c instead of c and for the bold row, I have repeatedly sed \textbf{}. For a more automated version of bold rows in tables, see for example here . Lastly, please note that I have also replaced the center environment by the \centering command as the former adds unwanted vertical white space arount the tabular.

\documentclass{article}
\usepackage{geometry}
\usepackage{array}
\usepackage{multirow}
\usepackage{mathtools}
\begin{document}
\begin{table}[h]
\centering
\setlength{\tabcolsep}{0.4cm}
\renewcommand{\arraystretch}{1}
\begin{tabular}{c|>{\bfseries}c|ccccccccccc|}
\multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{5}{c}{$\xleftarrow{\makebox[5.25cm]{}}$} & x & \multicolumn{5}{c}{$\xrightarrow{\makebox[4.75cm]{}}$}\\ \cline{2-13}
& & \textbf{-50} & \textbf{-40} & \textbf{-30} & \textbf{-20} & \textbf{-10} & \textbf{0} & \textbf{10} & \textbf{20} & \textbf{30} & \textbf{40} & \textbf{50} \\ \cline{2-13}
\multirow{5}{*}{\rotatebox{90}{$\xrightarrow{\makebox[1.25cm]{}}$}} & 50 &0& 0 &0&0&0&0&0&0&0&0&0 \\
& 40 & 0 & 0 & 0& 0&0 & 0 & 0 & 0 & 0 &0 &0 \\
& 30 & 0 & 0 & 0& 10 & 13 & 18 & 14 & 7 & 0 &0 &0\\
& 20 & 0& 0& 14& 19 & 22 & 24 &22& 18& 12& 0 &0\\
& 10& 0& 8& 20& 24& 27& 27& 24& 21& 12&0&0\\
y & 0& 3 & 12& 22 &25& 27& 30& 27& 24& 18 &4&0\\
\multirow{5}{*}{\rotatebox{-90}{$\xrightarrow{\makebox[1.25cm]{}}$}} & -10& 6& 16 &24& 27 &27& 30& 27& 24& 17& 8 &0\\
& -20 &0& 10& 18& 22& 27& 27& 23& 21& 12&0 &0\\
& -30& 0& 4& 14& 18& 22& 24& 18& 15& 13&0&0\\
& -40 &0& 0& 0& 0& 0& 0& 0& 0& 0 &0&0\\
& -50 &0& 0 &0&0&0&0&0&0&0&0&0 \\ \cline{2-13}
\end{tabular}
\end{table}
\end{document}
Regarding the request in the comments:
\documentclass{article}
\usepackage{geometry}
\usepackage{array}
\usepackage{multirow}
\usepackage{mathtools}
\begin{document}
\begin{table}[h]
\centering
\setlength{\tabcolsep}{0.4cm}
\renewcommand{\arraystretch}{1}
\begin{tabular}{c|>{\bfseries}c|ccccccccccc|}
\multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{5}{r}{\multirow{2}{*}{$\xleftarrow{\makebox[5.25cm]{}}$}} & x & \multicolumn{5}{l}{\multirow{2}{*}{$\xrightarrow{\makebox[4.75cm]{}}$}}\\
\multicolumn{1}{c}{} & \multicolumn{1}{c}{} & & & & & \multicolumn{3}{c}{in mm}\\ \cline{2-13}
& & \textbf{-50} & \textbf{-40} & \textbf{-30} & \textbf{-20} & \textbf{-10} & \textbf{0} & \textbf{10} & \textbf{20} & \textbf{30} & \textbf{40} & \textbf{50} \\ \cline{2-13}
\multirow{4}{*}{\rotatebox{90}{$\xrightarrow{\makebox[1.25cm]{}}$}} & 50 &0& 0 &0&0&0&0&0&0&0&0&0 \\
& 40 & 0 & 0 & 0& 0&0 & 0 & 0 & 0 & 0 &0 &0 \\
& 30 & 0 & 0 & 0& 10 & 13 & 18 & 14 & 7 & 0 &0 &0\\
& 20 & 0& 0& 14& 19 & 22 & 24 &22& 18& 12& 0 &0\\
y & 10& 0& 8& 20& 24& 27& 27& 24& 21& 12&0&0\\
in mm & 0& 3 & 12& 22 &25& 27& 30& 27& 24& 18 &4&0\\
\multirow{5}{*}{\rotatebox{-90}{$\xrightarrow{\makebox[1.5cm]{}}$}} & -10& 6& 16 &24& 27 &27& 30& 27& 24& 17& 8 &0\\
& -20 &0& 10& 18& 22& 27& 27& 23& 21& 12&0 &0\\
& -30& 0& 4& 14& 18& 22& 24& 18& 15& 13&0&0\\
& -40 &0& 0& 0& 0& 0& 0& 0& 0& 0 &0&0\\
& -50 &0& 0 &0&0&0&0&0&0&0&0&0 \\ \cline{2-13}
\end{tabular}
\end{table}
\end{document}

in mmto bothxandy. – leandriis Mar 03 '19 at 17:16