You might want to edit your eclipse.ini and give it more memory[1] ... It worked like a charm for me on my Mac. The linux boxes I use don't have this problem.
[1] The properties you want to change are: launcher.XXMaxPermSize, XX:MaxPermSize, Xms, and Xmx
Now that you mention it, it wasn't shy about how much memory it wanted to use either, but I'll give it a try next time I need to use Eclipse for something - thanks.
[1] The properties you want to change are: launcher.XXMaxPermSize, XX:MaxPermSize, Xms, and Xmx