This set consists of the Dead Man’s Hand Poker Table and the Let it Ride Roulette Table, each pictured below in the ordered mentioned in this sentence. Functionally, the two are similar; both can be hacked, both allow one to play just for fun, and both feature Simoleon amount options that are limited to 100, 500, 1,000, and 10,000. As far as I can tell, neither one can be sabotaged.
The functional differences are limited. With the poker table, you can invite people to join or practice a poker face. With the roulette table, your sim is no longer playing against any other sim, but just hoping the ball lands where they want it to go.
The main advantage these two pieces of premium content provide is atmosphere; they can make a casino feel more like a casino, and the atmosphere alone may be worth the 800 simpoint price tag for a lot of people.