Is it weird? Is it something I should do something about?

I have this coworker that I’ve barely talked to that added me on fb a while ago, and I added him back to be polite. I’m never on fb though so went a few months without checking it and when I logged back on I had like 30 messages from him. Not trying to be rude, but it honestly made me kind of anxious... we don’t work in the same department so it’s not like it’s someone I really know either