One of the best ways to get to know people is over a meal. People tend to feel more relaxed when eating. Conversation becomes more casual and natural. Part of it is that people don't have to talk constantly. Eating is a welcome distraction, especially for those who are a bit more quiet. Food is the center of attention, taking some of the focus off of guests.
Want to get to know your class/small group guests better? Take them out to eat. Or, even better, invite them to a meal at your home (there are usually fewer distractions). How about after church on Sunday? Or before the next group meeting? Make the contact sooner rather than later!
I remember visiting a class last summer with my wife. On our first Sunday, the secretary of the class (the teacher's wife), asked if we would like to join the class. Even though we didn't want to do so that day, both of us liked being asked.
Anyway, that week we were invited by a couple in the class to dinner at their home. We had a relaxing, delightful time. The meal was good, but the relationship that was begun continues to this day. We joined the class on our third or fourth "visit."
Do you like to eat? Invite. Share a meal with a guest. Get to know each other. You'll be surprised at the number who will stick--who will return to your class. Some guests may even come to know Jesus! Be revolutionary!