Depends on what type of poker players they are. If they are serious about their poker, then nothing that takes too much room on the table, gets their fingers messy and will get on the cards. A bowl of nuts, a bowl of pretzels, everyone's favorite brand of beer, soft drinks if you have some non-drinkers, maybe some coffee. Most guys eat before they leave to play poker. If they are coming for supper first, then they probably will be happy with a grilled steak or ribs. Usually the main thing is that the wife and children should be no-shows for the whole evening.