I really liked the Valhalla books which this animated film is based on. The film was also pretty nice, I do recommend people watching it if they ever get the chance.
In the animation and even the books, I think what he means by using the sword is that "don't just kill with it". Though he has no qualms about beating up Giants/Jotuns, that is his favorite past time. Hey, it is not like he is killing them, he is just beating them up to a pulp ^^