If you are having your wedding supper out of doors, that opens the door for many fun that would be hard to pull off inside. You can arrange competitions and activities based on the alfresco theme and carry that theme indoors if part of the supper is inside as well.
Contingent on where the reception will be held, you can arrange many fun based on the scene. whether it is the park or on a meadow, there are a myriad of fun you can plan.
let's commence with some basics based on popular wedding locations. One fun game for a winery marriage is a blindfolded wine tasting competition. If the bride and groom are wine drinkers, this might not a competition the bride and groom should be a part of, but instead guests and bridal party members. Blindfold perhaps a half dozen guinea pigs and have them do a blind taste test (specify something to clean the palate between sips). The volunteers should guess which wine is the pinot noir, which is the Cabernet, and so on. A bottle of wine is the obvious prize for the winner of this game.
Say you are having a reception at a country club on a golf course. It's possible your theme will include golf elements, so why not include golf in some supper fun or competitions? You certainly could head to the golf course for a "hole in one" contest, or have a driving contest to see which guest has the best stroke. As a simple, "who gets the centerpiece competition", you could have people guess how many golf balls there are in the floral centerpiece (which could decorate a plain large glass vase filled with flowers). Similarly, there could be a large vase or other clear container filled with golf balls at the reception somewhere and guests could guess how many golf balls are in the vase.
A silly game could be made on the dance floor by asking everyone to include their best golf swing into their dancing for one particular song.
Now, if your supper and ceremony are both to be held outdoors and guests will be milling outdoors, think about competitions or fun that can take place in the open airs and still keep to your level of formality or informality. For example, if the reception is being held at a green, perhaps guests might enjoy a "walk down memory lane". Prior to the reception, someone can use potted arrangets or arbors to create a little private lane, which guests can walk through. Along the path, guests will find pictures of the bride and groom at various stages in their lives. There should be a location for guests to record their thoughts and memories along the way as well.
If your bridal and supper are fairly casual, you can always tell guests ahead of time to prepare for a ball competition or some other fun in the open air activity. Women can bring a pair of sneakers. Just conceive the fun photos you'll get out of a rousing game of football or baseball played by women in dresses and sneakers and men in suits and sneakers!
You can specify a challenge activity involving barefoot dancing in the grass or a Frisbee toss in the backyard. Is there a pool in the yard where the supper will be held? Why not have a swimming activity for after the whole of the supper is done?