If you've flown lately, you know how much room it takes in the overhead bins or under the seats of an aircraft just for the carry-on luggage that passengers bring with them. At certain seasons of the year, you can expect about the same amount of personal belongings to show up for each person who comes to your family reunion. Set up a place for people to put it.
If it's cold or rainy out people will likely wear coats or rain gear to your family reunion. It's surprising how much room you need for it. A pile of twenty or thirty coats takes space! A pile of 100 coats is enormous. Here are some places you can put them if you need to.
Shoes are another problem if you're holding the reunion in a home with beautiful hardwood floors or nice rugs. You may want to put up a sign asking people to please remove their shoes. Provide a place in the entrance for them.
Most women don't want to carry their purses everywhere with them and anyone who brings a laptop bag may just set it down in the middle of the floor and let people stumble over it while he concentrates on something online. To solve these problems, set up a closet or shelf or some other place where people can safely leave personal bags and effects while they enjoy the reunion.