If a text cell begins with TeX: the TeX export contains the literal text that follows the TeX: marker. Using this feature allows the entry of TeX markup within the wxMaxima workbook.

Make more text fit on a LaTeX page

Use the LaTeX package geometry to specify the size of the borders.

You can add the following line to the LaTeX preamble (for example by using the respective field in the configuration dialog (Export->Additional lines for the TeX preamble), to set borders of 1cm)

\usepackage[left=1cm,right=1cm,top=1cm,bottom=1cm]{geometry}