There are settings to adjust the height and width that are set separately. In the ini or preference file, there should be a section for window settings. It should be the lines under the line that is
There are bunch of settings, but these are relevant to what you need:
HeaderColumnWidth sets the width of the split name column.
DataColumnWidth sets the width of the remainder of the rows.
HeaderColsHeight sets the height of the column header line.
RowHeight sets the height of the rows for the splits.
I think these settings are enabled in the Mac version. I am the programmer for the Windows/WINE version, so I am going on how it should work.