This is a minimal example using the LaTeX booktabs package which you can use & modify to create your own table.
\documentclass{scrartcl}
\usepackage{booktabs}
\usepackage[utf8x]{inputenc}
\begin{document}
\begin{table}[h!]
\begin{center}
\caption{Minimal booktabs example.}
\label{tab:table1}
\begin{tabular}{l|c|r}
\toprule % <-- Toprule here
\textbf{Column 1} & \textbf{Column 2} & \textbf{Column 3}\\
$\alpha$ & $\beta$ & $\gamma$ \\
\midrule % <-- Midrule here
A & 10.23 & a\\
B & 45.678 & b\\
C & 99.987 & c\\
\bottomrule % <-- Bottomrule here
\end{tabular}
\end{center}
\end{table}
\end{document}Render it using
pdflatex booktabs.tex
The table looks like this:
