I have talked to some residents from some residencies at my home program.
These small chat dinner things can make you stand out among the pile or push you into the DNR list.
But, from my observation, the cool things to talk about in these events are stuff to do in the local area for the next 3-5 years (restaurants, hiking trails, events, annual theatrical events, type of available schools for your kids, etc...) The strategy for this is to demonstrate interest in the program and the local community, and also open up your interests / hobbies in order to push the convo into something substantial that will connect you with some of the residents in the program.