If you're planning on inviting children to your wedding you may want to consider supplying them with an activity to keep them busy.
Really little ones will have to sit with their parents but if they're over 18 months you can have coloring books and crayons available to them. Older kids may need something more exciting so visit a local toy story for activity books, small games they can play at the table or if you can afford it and have a large number of kids you may want to hire a magician, clown or other kid-friendly entertainer.
It's okay to set up a designated kids' table but if you're not sure if a child is old enough to sit away from his or her parents just ask.
Another option if you don't really want children there but can't say no, ask the reception venue if they have a room you can use as a "daycare center." Hire a babysitter or two and stick it with kid-friendly foods, games and even some DVDs if there's a TV. Parents will be close by to pop in or in case of an emergency and still be able to have a great time at your reception.