Sounds like a normal amount tbh, they do eat a lot!
The lentil bites sound nice, ignore the snippy comments. They always crop up if someone mentions a lentil.
My son is 17m and here’s what he eats in a day:
Breakfast: two weetabix or fortified porridge with a scoop each of flax, hemp, ground almonds and ground walnuts, topped with raspberries and soy milk, and an orange or banana.
Lunch: homemade baked beans on wholemeal toast, or a homemade curry (for example spinach and chickpea) with coconut rice, or a lentil dhal with a sweet jacket potato, or homemade veggie shepherds pie and veg, or avocado with ground almonds on toast that kinda thing. An orange or banana or apple. Cup of oat milk.
Mid afternoon snack: hummus on a rice cake, or some marinated tofu pieces, or a homemade butter bean and garlic dip with breadsticks
Dinner: similar to lunch but a lot more veg included and on the side, sometimes homemade soup and bread (I add loads of edamame or broad beans to the soup), or a veggie version like deconstructed Mexican fajitas, maybe lentil bolognese with linguine or spinach pasta, spinach bites on the side.
Supper: bowl of coconut or soy plain or Greek yoghurt with berries and some sliced fruit. Cup of oat milk.
If he’s gaining weight as he should be according to your GP/HV then I wouldn’t faff around listening to anyone else tbh, he’s doing fine. Sounds like you put a lot of effort and card into his diet, well done! Doesn’t it feel with a toddler like you spend the entire day preparing food, watching them eat, or cleaning up after them 🤣