If babies kept eating at the same pace as they do during their first year of life, they'd be blimps. That's something helpful to remember...now, he's on a maintenance diet, not a "growing during the first year" diet. :)
My daughter is 19 months, but I'll give you an example of her diet. Breakfast is a GF pancake (made with cinnamon and coconut in it, but NO syrup or butter.), cheesy scrambled eggs, or GF Rice Krispies or Honey Nut Chex with milk, and 8 oz. of water.
Mid-morning snack is usually and apple or banana with GF pretzels.
Lunch...tuna salad (just tuna and Hellman's) with tortilla chips, prunes, a cheese stick or a yogurt, papaya, GF chicken nuggets (2), turkey dogs, Spam, apples and bananas, pears, roast beef sandwich on tapioca bread, chicken rice with broccoli, sardines, etc...not all at once, of course! I pick a few.
Afternoon snack...banana Mum Mum, homemade goodie, pretzels, puffcorn, random things.
Dinner is ALWAYS what we eat. Anything from tacos, nachos, stir-frys, casseroles, soup and sandwiches, meat with veggies, etc.
NOW, here's the thing. She's still nursing, but besides that, ONLY drinks water. No juice, no dairy milk or substitutes, etc. I have found between my two children that drinking water really promotes my little one's healthy appetite. My oldest drank a lot of milk and was a VERY poor eater, so check how much milk he's drinking. Any more than 16 oz is too much, really...and you'd be surprised how quickly they can down 2 cups of milk. Also, many toddler cups are 10 oz!!
I would recommend you just serve up a wide variety of things and let him eat what he will and leave what he won't. He won't starve, like you said...and hopefully he'll become a little more adventurous.
But your doc is right...well within the range of normal. My first one was like this, and my second one is my super eater. :)