Was there ever a diagnosis or fix for this issue? I've just hit exactly the same thing.
I have two nested ng-repeats which build a small table (<10 rows x <10 cols), updated every few seconds. The corresponding tab in Chrome quickly uses >700MB of memory.
Looking at a heap snapshot in Chrome, I see thousands (>5000) of these objects: "$get.Scope.$new.Child". They retain a lot of memory (>15MB in my case) relative to other stuff in the heap. But I don't know where they are coming from.
From this thread, it appears that using a directive instead of the inner ng-repeat is a kind of workaround, but that's quite difficult and it seems like it shouldn't be necessary.
Any clues gratefully received...
Thanks,
Richard