Based on Mixing It Up with Purpose [1]
As students enter the cafeteria, give each student a playing card. Tell them to sit at a table where everyone has a card of the same suit or at a table where everyone has a card of the same type (everyone with an eight sits together; everyone with a jack sits together). At each table, have a list of conversation prompts. Here are some examples:
[Source for prompts: http://www.tolerance.org/magazine/number-26-fall-2004/alternative-success [2]]
Links:
[1] http://www.tolerance.org/magazine/number-38-fall-2010/mixing-it-purpose
[2] http://www.tolerance.org/magazine/number-26-fall-2004/alternative-success