I'm not sure what happened but for some reason I can't reduce the height of my table rows in Gantt Chart View. Even if I reduce the font size, I cant decrease the row height so that there isn't all that extra WHITE SPACE, as shown in the below screenshot. Is there some setting I'm missing?
One thing that can drive row height is text above and/or below Gantt bars. I note in your screen shot you have text above the summary line Gantt bars. Change that to the left or right of the bar and see if that allows you to reduce the row height.
You might also check the Bar Styles and insure all bars are set to display on row 1. Gantt bars can be set to display on any one of four rows.
I also note you have text wrapping active in your view table. That doesn't appear to be the driver but you may consider turning text wrapping off.