They are lammers/buttons. These are markers used in casino and poker rooms for a variety of things & made/sold by many casino equipment manufacturers.
The Lay & the On/Off buttons are mainly used on the craps table. The others with numbers/denominations are used at the roulette table to indicate cash values of color stacks, dropped off in dealer trays by chip runners to indicate amounts of chips being bought, used for buy-in chips to tournaments, etc... Some of the dealers on the board can probably give you a better description of some of their other uses.