It could indeed!
The very well known Swedish children's song Bä, bä vita lamm (a translation of the English Baa, Baa, Black Sheep) ends "och två par strumpor åt lille, lille bror". This has (maybe just jokingly) sometimes been translated to "and two pairs of socks ate the tiny little brother" rather than "and two pairs of socks for the tiny little brother".
Yup, your sentence would be the natural way of expressing it, although both would be correct. Since What is the boy eating is the more logical translation of Vad äter pojken, hardly anyone would interpret it as the boy being eaten, except in the söi pikku pikku veljen example.
Looks like they use gnawing for that in Swedish. Although, the English for metaphoric corrosion is more commonly eating at rather than just eating.
Vad gnager dig?
When I hover my cursor over 'vad', both "what" and "how" are suggested as meanings. I don't understand why "how is the boy eating" wasn't acceptable. Maybe his mother has been trying to teach him good table manners, and he's gone to visit his grandmother, and the mother asks her, "how is he eating now--in a nice, gentlemanly way?" Someone below asked about this translation, and you said "hur", not "vad" would have been used. I see a grammatical distinction--at least in English 'what' is a pronoun, while 'how' is an adverb--(except maybe in something like "Do you know how?" where it is perhaps a ...pronoun?...standing in for a noun clause "how to do it". But then "how" would be the direct object of "know".).
So I guess my question is, is 'hur' only and always an adverb, and is 'vad' only and always a pronoun? And then, IF 'vad' is only a pronoun, why is 'how' suggested as a meaning for it in the lesson?