\resizebox{\textwidth}{!}{%
\begin{tabular}{@{}rrrrrrrr@{}}
\toprule Steps $r$ & $k=16$ & $k=24$ & $k=32$ & $k=40$ & $k=48$ & $k=56$ & $k=64$ \\ \midrule
4 & --- & --- & --- & --- & --- & --- & --- \\
8 & --- & --- & --- & --- & --- & --- & --- \\
12 & --- & --- & --- & --- & --- & --- & --- \\
16 & --- & --- & --- & --- & --- & --- & --- \\
20 & --- & --- & --- & --- & --- & --- & --- \\
24 & --- & --- & --- & --- & --- & --- & --- \\
28 & --- & --- & --- & --- & --- & --- & --- \\
32 & --- & --- & --- & --- & --- & --- & --- \\
40 & --- & --- & --- & --- & --- & --- & --- \\
48 & --- & --- & --- & --- & --- & --- & --- \\
64 & --- & --- & --- & --- & --- & --- & --- \\
\bottomrule
\end{tabular}}