I created a post earlier on the same topic (Vertical alignment in tables). I got an answer but it triggered another question.
Below the solution that has been provided. I would expect vertical centering but the text goes on top of each cell. Playing with p, m, and b to align vertically doesn't seem to work here. I have probably missed something...
\documentclass{article}
\usepackage[english]{babel}
\usepackage{array}
\begin{document}
\begin{tabular}{ |m{2cm}|m{2cm}|m{2cm}|@{}l@{}}
\hline
x &
x &
x &\\[5mm]
\hline
\end{tabular}
\end{document}

\\[..]is added afterwards and thereforemdoesn't take the full height into account. Is that correct ? Is there another way to specify the height that would be considered by them? – ed82 Jan 21 '13 at 17:10\\[]and do use\arraystretchthe strut is enlarged for all rows and inp/m/tcolumns the first column gets a strut with the height and the last row gets a strut with the depth, but often simpler is just in any cell of the row use\vspace*{2cm}before and/or after the main text of the entry, that has a more direct effect and the space probably increases in a way that is more predictable – David Carlisle Jan 21 '13 at 17:14