There are pros and cons to each seating method. There is something special about having different generations of families together around the table to break bread, tell stories and laugh at each other's jokes. Even if you're visiting together all day, the pace of a meal allows you to slow down and come together as a family. On the other hand, the pace of an adult's meal can be much slower than a child's and kids may feel restless at the table waiting for adults to finish or become bored listening to adult conversation. One of the benefits to having a separate kids table can be the camaraderie building among cousins and other young relatives who may see each other infrequently.
(Image by Flickr user Abby Batchelder licensed for user under Creative Commons)