\documentclass{article}

\begin{document}
  % here's a table
  \begin{table}[]
    \begin{tabular}{l|l}
    $(\lambda x.x)y$  & given \\
    $(y)$             & $\beta$-reduce $y$ for $x$. \\
    $y$               & done 
    
    \end{tabular}
  \end{table}

\end{document}