I have a coworker who keeps on asking me for small favours that he can do by himself.
For example, I entered our break room to drop off my lunch when, after seeing me, he will ask me if I can close the window and turn off the electric fan because he's about to leave. He then ends up staying for another half hour. He does this almost every time.
As another example, he keeps on asking me to return things he borrowed from our coworker's table, which he can do by himself. I don't mind doing this occasionally but it's becoming a pattern. I am busy with my own work and schedule so interrupting me for things that he can do by himself doesn't seem right.
I've heard that he does this to everyone, interrupting my coworkers as well. It seems to me that this guy is not a bully he's just unaware that he keeps inconveniencing others out of laziness. Overall, he is a nice guy. We've addressed his behaviour, in the moment, before but it seems that after a while he reverts to his old pattern.
How do I deal with this without offending him?