\documentclass[a4paper,11pt]{article}
\usepackage[margin=2cm]{geometry}
\usepackage{booktabs}
\usepackage[table]{xcolor}
\usepackage{multicol}
\usepackage{multicoltab}

\begin{document}

\begin{multicols}{2}
\section*{Table options}

\begin{multicoltab}[width=.96\linewidth,row-sep=.6ex,break-penalty=50]
  {@{}p{.30\linewidth}X@{}}
  \mchead[\toprule][\midrule]
    {\textbf{Command} & \textbf{Effect}} \\
  \rowcolor{gray!15}
  width & Changes the width from the default \texttt{\string\linewidth}. \\
  row-sep & Adds vertical space after every row. \\
  \rowcolor{gray!15}
  break-penalty & Adjusts TeX's preferred break after a normal row. \\
\end{multicoltab}

\end{multicols}

\end{document}