With Mario's hint, I could use tabulary to get this result.

\maketitle \begin{table}[hbtp] \footnotesize \centering \begin{tabulary}{1.0\textwidth}{C||L|L|L|L} \hline & Function & Pre conditions & Post conditions & Constraints \ \\ \hline\hline R1 & An election official is assigned for each precinct & Precincts and elections officials are created & Unique one on one mapping from an election official to precinct & Before voting starts\\ \hline \end{tabulary} \caption{Requirements before voting starts} \label{eoRequirements} \end{table}