When you have more repository tabs than will fix in the available width, there are arrows to scroll the tab bar.

These arrows seem to jump the bar some fixed number of pixels.  The amount it scrolls for each click is far too small.  It seems to be just 20 pixels or something.  It takes several clicks just to scroll the width of one tab.  In my case it takes 13 clicks to scroll one tab.

My suggestion would be to have each click scroll one whole tab to make navigating the tabs much easier.