At this age toddlers have just gained the capacity to rotate their arms and release an object. They always want to practice new skills and delight in doing so. They are also declaring that the meal is over. At some other time it would be good to have them practice throwing a ball or something appropriate. When a child throws food regularly it often means they are trying to get attention. Put the child away from the table and remove their chair and their food. In about one hour offer the same food again. It is important for meals to be a pleasant time of interaction and not a place for arguing, TV, or people on electronics. A child who is bored or feels left out may throw food to break into the conversation.