\documentclass[a4paper,12pt]{article}
\begin{document}
\parindent=0in

% Tables
% Example I

Things to note:
\\tabular command are left, center, right specifies the justification.  
\\ a bar spcifies to draw vertical line in between the columns
\\ two slashes specifies to start a new row
\\ Also note how a horizontal line is specified, and a new line is entered 
\\ {\bf Why is this text below the table?}


\begin{table}
\centering
\begin{tabular}{l|cr}
x & y & z   \\
\hline
1 & 3 & 4 \\
3 & 2 & 1
\end{tabular}
\caption{caption text goes here}
\label{some label}
\end{table}

% Example II

\begin {center}
\begin{tabular}{|r|r|r|r|}
\hline
Output		& Voltabe Range (v) &	Frequency (Hz)	& Notes \\
\hline
\hline
Linear sawtooth	& 0 min to 10 max   &	100 to 1000	& 9/10 T rise, 1/10 fall \\
\hline
Pulse		& -14 min to 14 max &	100 to 1000	& 9/10 -ve, 1/10 +ve \\
\hline
Pulse		& 0 min to 2 max    & 	100 to 1000	& 			\\
\hline
\end{tabular}
\end{center}

\end{document}