S.S.
I agree with several of the moms out there. This is a phase where she is trying to see what power she has over you. Don't feed her. She will feed herself if she is hungry. Kids at this age don't eat as much as they used to when they were younger. Tell her that she is a big girl and that she can feed herself. Only babies get fed and she is not a baby. If she stops eating and wants to leave the table, tell her that the meal is over when she leaves and that she won't get any food until the next meal. Stick with it. She'll catch on. My 2 year old wants to leave the table to play. If she refuses to sit in the booster, then when she leaves the table, the meal is over. I give her reminders when I see that she is starting to get off the chair. She quickly changes her mind so she can eat.
You don't want to be like a friend of mine who is chasing her son (18 months) around the house with a spoonful of food.
Good luck!