One fun and active game that can be played by all your guests, including grandma as well as the young children, is “Want It Now."
In this game, you designate a master of ceremonies (if you have a DJ for your wedding reception, [which could be us, wink wink] this person can serve as the MC).
The MC would have a list of “wants” prepared before the reception, or they can come up with it on the fly if they understand the rules of the game.
Everyone sits at their tables, and waits to hear the command.
The MC says he wants a person with, for example, painted toenails. Everyone with painted toenails will run to the front of the room, toward the MC.
Each time a table sends someone to the front first, they get a point.
Points should be tallied during the course of this game and prizes (maybe some wedding favors or centerpieces) awarded at the end of the game.
Be sure to have some obvious “wants”, as is the painted toenails, or someone with a mustache or a child with a pink dress.
You should also include some surprises, like “a man with a high-heel shoe” which will require a man to find a woman at his table with a high-heel shoe and run up to the front of the room with the item.