Changing the spacing on a document-wide basis is done for different document settings using different packages. The geometry package controls the overall margins and text area of the document. The package must be called in the preamble of the document and specified when called.

The geometry package is called with the use package command, followed by the options, and then the package name, like this:
usepackage[left=2cm,top=1cm,right=3cm,nohead,nofoot]{geometry}

The LaTeX package rotating is needed so include
\usepackage{rotating}
in the preample of the document.

Every single column label has to be included into
\begin{sideways}MyColumnLabel\end{sideways}
Thats a bit awkward, but thats the way it is….

An example from the blogpost mentioned above:
\begin{tabular}{rr}
\hline
\begin{sideways}Paper\end{sideways} &\begin{sideways}Static\end{sideways} \\
\hline
HAR1994j & Journal \\
SWRT1996c & Conference \\
\hline
\end{tabular}