I recently edited a table with data. One column contained a text description which was rather long. So I wondered if there is a way to reduce the font size of the whole column rather than for each cell individually. And this is what I figured out:

\usepackage{array}
...
\begin{table}[ht]
\caption{Table with decreased font size of description column.}
\begin{center}
\begin{tabular}{rl>{\footnotesize}b{7cm}rrr}
\hline
 & Name & Description & Value 1 & Value 2 & Value 3 \\ 
\hline
...
\hline
\end{tabular}
\end{center}
\label{tab:tab1}
\end{table}

Using the column type b{width} it is further possible to limit the cell width. Latex adds line-breaks where necessary.

For details, see array package documentation