In the commit history view there are columns 'Graph', 'Description', 'Date', 'Author' and 'Comment'.
If one hovers over the gaps betweeen the column headers a re-size cursor appears to resize the column left of the cursor.

This works between 'Graph' and 'Description' but not between 'Description' and 'Date'. Also resizing behavior between 'Date' and 'Author' is unintuitive.