No, Japanese high schools do not have "viking kyoshoku." There's no such thing as a "viking kyoshoku" in Japanese culture or education. The term appears to be a combination of unrelated words:
* Viking: Refers to the Norse seafaring warriors of Scandinavia.
* Kyoshoku (給食): Means school lunch.
It's likely a misunderstanding or a made-up term. Japanese school lunches are quite different from anything associated with Viking culture.