A token is like the $1 metal "coins" made by the casinos. You feed them into the slot machines. Also used on table games sometimes. Comes in other denominations too.

A silver strike is a special metal piece, placed inside "silver strike" slot machines. When you hit the right combination, one or more of these pieces drops out of the slot. It is already encased in a plastic holder (so it doesn't get scratched). The typical one is redeemable for $10, though there are other denominations too. Most have a silver center slug with a gold-colored outer ring around it.