Jack Daniel
Legend
That said ... I think the difference is subtler (I guess) than I read you to be saying. The novelist makes up the sequence of events, and narrates them; the TRPG table makes up (or generates) the sequence of events, and one of them types them up after-the-fact. The big differences I see are 1) in the process, the novelist typically makes up the events as they're doing the writing, whereas the gamers are generating the sequence of events, then writing them up later (making that more like, as you say, journalism or history--but there are novelists who work from outlines, which is closer to what's happening with gamer notes than the work of a novelist who free-writes); and 2) in the novel at least, there's more singularity of authorship than there is at (most? many?) TRPG tables, which plausibly makes it easier to control what happens in a novel--so things like theme and subtext are easier to manipulate/choose. (I think there was going to be at least a third difference, but it's fallen out of my head.)
That isn't quite the point I'm making. A story can be made up (novelist) or a recounting of events (journalist). A story can have a singular author (novel) or a many (writer's room TV spec). The point is that a story is in some sense a defined object, whereas a tabletop RPG campaign in actual play is more of an ongoing process.