Hypothetically, it appears that it is important for this child to sit and eat at the kitchen table. It also would appear that sitting and eating at the table is a socially acceptable behavior for the family of this child. For some families, this behavior may not be a priority or a concern. However, in our scenario... the family desires this behavior.
So... do you think this behavior will benefit the child?
Will this behavior (of sitting and eating a meal at the table) lead to the child learning other behaviors that will increase the child's independence, broaden the child's behavior repertoire?
For example, if the child begins sitting and eating a meal at the kitchen table, will this behavior become rewarding in and of itself... will opportunities to learn new behaviors occur with the demonstration of this behavior... will more social interactions occur... will other family members enjoy being around this child during meals, etc.?
Consider the investment necessary to increase a behavior.... is this behavior a priority among others? Will this behavior (the new or increased behavior) create more opportunities for victories?