Thread:Support/Expanding a message group is very slow

It's not a new problem, but i never bother to ask about it: if you open statistics for a language and click "expand" on a large message group, like MediaWiki extensions, it takes a few long seconds to open it, and while it is being opened, different browsers behave differently:
 * Firefox is completely stuck and i can't even switch tabs. (I'm using the Nightly version, but it's the same in all of them.)
 * Internet Explorer (8 and 9) becomes slow, but is able to switch to another tab after a few moments.
 * It takes Google Chrome a few seconds to expand it, but while it happens, i can smoothly switch to any other tab.

Of course, Mozilla and Firefox should improve their browsers in this regard, but it would be cool to make this work faster in the first place.

I don't use Chrome because its RTL support sucks (saw it coming?). To make things faster i use "Suppress completely translated message groups", but sometimes seeing them all is useful.