This is the Milestone table, generally you'd replace this with your own table. There are some very tight connections however towards the Milestone title and Date in the formulas and automations. This is done to deduplicate the votes and make the counters work properly.
This table stores the votes temporarily until they get archived, there are no formulas in this table.
This table stores the votes, there are no formulas in this table. Celebrations get added to the archive every time the automation rule runs, this is done to make sure the table doesn't grow to a unusable size.