The majority of men are delusional. With the exception of a few non delusional men, there’s no such thing as a friendly chat. They delude themselves into thinking it means that women are expressing interest in them.
The next time he tries to give you a gift, tell him that it’s against work rules to accept gifts. Try to limit conversation with him as much as possible. Tell him that you’re busy and you can’t stop to chat or find a way to extricate yourself from the situation.
If you prefer the more direct approach, you could tell him that his behaviour is inappropriate.