My son is 11 month old and he started walking for a while (need to hold onto something to walk).he always wants to get off the chair to walk too but he would stay in the chair when we eat.we also feed him at the same time so he understands it is meal time.you may try to eat with him together so he could build the dining habit? Just make sure you would not give in and let him get down before dinner is done.he tries it once,he will do it again.however,we may let him get off the chair (if the food is not There) when we eat out.we do not want to disturb other diners in the restaurant.but we would not let him off too long maybe 5-10 minutes then he must stay in the chair for food.if he is not eating,we will give him a toy or keep engaging him in conversation like telling him what we eating and asking how he is doing.if he is good,we would give him compliment.as long as he feels he is engaged and not neglected,he is happy.