Here is a comparison of those two CPUs. Both are dual core CPUsPassmark CPU benchmark scores
Core i3 330M @ 2.13GHz = 1978
Core i7 620M @ 2.67GHz = 2731
You would probably notice the better performance of the 7 620M, especially when you do heavy multi-tasking multiple Word documents open, with MS Powerpoint or Excel also running.
For web browsing, you probably won't notice the difference as much.