This may not be helpful, but I just want to pose the question. If the panel is required because of the use of Tabs, and the panel is the cause of the scrolling, what if you show/hide just the repeating section, removing the panel? It looks like the repeating section is the only control for that tab. Since the repeating section auto grows on its own and is then limited by the panel. Maybe this isn't an option, but wanted to throw the idea out there.
Insert Repeating section inside Panel, Go to Panel Configuration settings. In advanced Section Resize at Run Time selected as YES
Thanks for the replies and suggestions - none of that worked for me - but I was able to use css as suggested by chaitra and got it working !
Thanks Chaitra for your continued help!