\documentclass[12pt,a4paper]{report}
\usepackage[latin1]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\author{Wim Bertels}
\begin{document}

\begin{tabular}{l | l | l}
\textit{Schema} & \textit{Name} & \textit{Description} \\
\hline
latex\_test & t4bruce1 & This function and so on enter\\		another enter,\\		just one more.\\         \\
latex\_test & t4bruce2 & This function and so on enter\\		another enter,\\		just one more,\\		so now have even one more.\\         \\
\end{tabular}

\noindent

% with a \\ replaced by a newline, doenst help
\begin{tabular}{l | l | l}
\textit{Schema} & \textit{Name} & \textit{Description} \\
\hline
latex\_test & t4bruce1 & This function and so on enter\newline		another enter,\\		just one more.\\         \\
latex\_test & t4bruce2 & This function and so on enter\\		another enter,\\		just one more,\\		so now have even one more.\\         \\
\end{tabular}

\noindent

%\begin{tabular}{l | l | l}
%\textit{Schema} & \textit{Name} & \textit{Description} \\
%\hline
%latex\_test & t4bruce1 & This function and so on enter\\		another enter,\\		just one more.\\         \\
%latex\_test & t4bruce2 & This function and so on enter\\		another enter,\\		just one more,\\		so now have even one more.\\         \\
%latex\_test & t4bruce3 & This function and so on enter\\		another enter,\\		just one more,this is a very long line without an enter, just one more,this is a very long line without an enter\\		so now have even one more.\\         \\
%\end{tabular}
%
%\noindent

\end{document}