\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 and heading rules}

\begin{multicoltab}[width=.96\linewidth,row-sep=.6ex,break-penalty=50]
  {@{}p{.30\linewidth}X@{}}
  % Use mchead when the heading rules and cells must be repeated together.
  \mchead[\toprule][\midrule]{%
    \rowcolor{gray!20}%
    \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. \\
  natural-widths & Selects globally synchronized or per-row natural widths. \\
\end{multicoltab}

\end{multicols}

\end{document}