How do I know how many people are on the Waitlist?

When you click on a table on the Waitlist a number will be shown with the 'Join Waitlist' or ‘Leave Waitlist' button. The number on the list will also be shown when the Waitlist column is active in the Lobby.

In the My Waitlist area the number will also be shown in the column data area under 'Waitlist'. Where there is a number that is split e.g. 2 of 3, this indicates that you are second in line to have the choice to sit at a table.