I host a lot of board game days and...yes.

One thing I do that helps is get people to RSVP with a specific arrival time, and do my best to have a game about to start around that time.

If you show up unexpectedly, then I'm not going to feel bad about you sitting out for an hour or more.

People unexpectedly bringing a partner/friend who is not really that into board games is the absolute worst thoguh.