\usepackage{booktabs}

\begin{table}[!htbp]
\centering
\caption{...}
\begin{tabular}{l l l}
\toprule[1pt]
a & b & c \\
\midrule[1pt]
a & b & c \\
\hline
a & b & c \\
\hline
a & b & c \\
\bottomrule[1pt]
\end{tabular} \label{table_a}
\end{table}