forget about a bowl and spoon. Put the food straight on the tray, in easy chunks that can be picked up and eaten and let him go for it. If he doesn't want to be spoon fed, then just don't do foods that need to be eaten with a spoon
Just offer variety, and stick with it, and he will get there. If you want him to be eating more food then maybe make sure you aren't offering too much milk in whatever form he is taking it.