So it will help to keep track of them all. Tomorrow we'll want to know who voted for who and so one and so forth, so it'll be pretty handy to look at. And it will help for counting votes too - that can get confusing when there are so many people. And finally, in a game this large it can be easy to forget someone who is being very quiet, which is often a Mafia technique. This way we can just look at the table and be reminded who all's playing and who hasn't been sharing recently.