Let's go with the possibility that Sponge Bob (since that was already mentioned) on the television during meals is one of the variables keeping the child away from the kitchen table. Because... Sponge Bob is so meaningful and reinforcing to the child... eating at the table is just not too exciting. However, eating is still desirable.
What if you communicate (verbally and by some sort of visual)... "First eat one bite (chew and swallow) while sitting at the table ... Then... Sponge Bob for 1 min. (great if it can be paused on a DVD or recorded earlier).
An easy to use, but good timer would be very helpful. You may even want to teach the child to set the timer for the time to sit at the table and/or the time to watch Sponge Bob. The more the child can learn to self-manage.. the better. However, it may have to come in small steps - and build to self-managing.
So, when the timer goes off... back to the table "First eat 2 bites while sitting"
Then Sponge Bob for 2 minutes, etc."
I've included a couple of visual supports for "First _____ Then _____" Usually I velcro a picture representing what is first... and what comes after... However, you can write it in, etc.
One of the First --- Then cards was made for a child who was highly interested in weather. This is an example of how to use one's interest to increase motivation.
Get back to you soon!