the Gantt Chart consists of two parts: the table on the left and the timeline on the right. I know one can collapse the table completely by clicking on the arrow between table and timeline. Also it is clear, when the table gets more than about 50% of the screen a scrollbar shows up for the table (so timeline remains always more than about 50% of the screen).
But how to change this ratio? So how to pull that the table only has 30% and the timeline 70% of the screen? As the table has the availability of a horizontal scrollbar this should be no problem.