I'm assuming the core i3 is the older generation? They don't use the newer integrated graphic [intel hd 3000] so I would go witht he i5-2410m with nVIDIA GT 540m. nVIDIA has a history of strong driver support and you will get more out of the i5-2410m. You pretty much want all the power you can get. You will benefit from more RAM but you can always upgrade the RAM yourself. Go with the first one!
Thanks alot for your reply. That makes much sense. I was only considering the I3 laptop because of the screen size and as both of them have comparable price I thought If the I3 is adequate for the video editing job then I would go with it. However, I am now convinced the I5 laptop is the one I should buy.
Thank you very much guys.