EXAMPLES:
sage: from sage.combinat.output import tex_from_array
sage: print tex_from_array([[1,2,3],[4,5]])
{\def\lr#1{\multicolumn{1}{|@{\hspace{.6ex}}c@{\hspace{.6ex}}|}{\raisebox{-.3ex}{$#1$}}}
\raisebox{-.6ex}{$\begin{array}[b]{ccc}
\cline{1-1}\cline{2-2}\cline{3-3}
\lr{1}&\lr{2}&\lr{3}\\
\cline{1-1}\cline{2-2}\cline{3-3}
\lr{4}&\lr{5}\\
\cline{1-1}\cline{2-2}
\end{array}$}
}