What does this mean if he messaged me on FB?

[Varun]

My guess is that he's interested in you. He needs some reason to get in touch (and believe me, when you want to connect with someone you happen to like, you can come up with really weird ones.)
The basic question is: are you interested in him? If so, give him a chance to follow up. Respond and reply on a for a month or two (or whatever duration of time it takes to have 10-12 messages) on a 'just friends' type of note. DON'T tell him you're interested in being 'just friends' - let the question fo unanswered for now - but spend some time figuring out what he is interested in and give him the time to ask you out. If you happen to be in the same city or free on the same day, point that out to him. If he's interested, he should take the hint.
If you're not interested in talking to this guy, cut it off appropriately. Don't respond.
If you like the guy but only as a friend, then same as #1, except that you have to tell him something about 'being friends' early on. Try 'Hey, friends are always useful' or some variant thereof. Something that says you would like to count him as a friend, but at par with all your other friends. He'll get the message.