There are 23 dishes ranked on this page. The lightest is Latok (Sea Grapes) at 30 kcal per 1 small plate, the heaviest is Gado-Gado at 390 kcal per 1 plate (vegetables, lontong, tofu, tempe, half egg, peanut sauce, emping), and the average lands around 174 calories a serving. 21 of them come in under 300 calories.
The spread here is narrower than most categories, about 360 calories between the lightest and the heaviest. That means portion size and what you order alongside it matter more than which dish you pick.