Usually child meals are offered purely for children over 2 yrs - your ds will be classed as an infant! I would double check with klm to be sure your ds will qualify as there could be health and safety issues with providing a child meal for an infant.
I would take food you know he likes because the food might arrive at the wrong time - too late, or just as he has gone to sleep. When we last flew with KLM long haul the kids meal was macaroni cheese, a yoghurt, fruit, dessert thing. Not too bad. But by the time it arrived (2 hrs after take off) it was so late that our DD was nearly asleep.
My ds (16 months at the time of travel) are going to Saudi Arabia with KLM the second week of Jan. KLM's website states they do children's meals which don't need to be prebooked, I was just wondering if anyone can tell me what the meals are like? If they aren't so good i'll pack more things for DS to eat instead.