TeX source:

\begin{array}{l|l|l|l|l|l|l}\mathrm{x} & 0 & 1 & 2 & 3 & 4 & 5 \\ \hline \mathrm{f}(\mathrm{x}) & 5 & 3 & -2 & -1 & 3 & -2\end{array}