\documentclass{article}
\usepackage[table]{xcolor} % <== cells coloring
\begin{document}
\renewcommand{\familydefault}{\sfdefault} % <=== sets serif font
\newcommand{\cc}{\cellcolor[rgb]{0.847, 0.894, 0.737}} % <=== cells cloloring shortcut
\begin{table}[h]
\centering % <=== center the table
\renewcommand{\arraystretch}{1.1} % <=== increase cells padding
\begin{tabular}{|c|ccc|}
\hline
\shortstack{\\[1ex] y = numbers of\\ times city\\ name is stated\\[-2em]} &
\multicolumn{3}{m{7em}|}{\centering x = number of bars of signal strength}\\ \cline{2-4}
& \multicolumn{1}{c|}{1} & \multicolumn{1}{c|}{2} & \multicolumn{1}{c|}{3}\\ \hline
1 & \cc 0.01 & \cc 0.02 & \cc 0.25 \\ \cline{1-1}
2 & \cc 0.02 & \cc 0.03 & \cc 0.20 \\ \cline{1-1}
3 & \cc 0.02 & \cc 0.10 & \cc 0.05 \\ \cline{1-1}
4 & \cc 0.15 & \cc 0.10 & \cc 0.05\\ \hline
\end{tabular}
\end{table}
\end{document}