I’ve read a few books from the late Victorian era through to the 1920s which have an odd literary device where, after the narrator has spent most of the story describing one or two key events, glosses over lots of interesting stuff as if they’re hitting the “fast-forward” button on the story for some reason.
Take Beau Geste as an example - most of the story focuses on the Geste brothers running away to join the French Foreign Legion and some of them getting involved in a planned mutiny at a Saharan fort.
Then, following the resolution of that particular story aspect, several characters embark on a long journey across French West Africa which is handwaved away with something akin to “And a lot of cool stuff happened, but I’m not going to describe it in any detail because it’s really too incredible to go into here. Soooooo, moving right along to the next bit…” which is frustrating because some of it sounded rather interesting, at least as much as some of the stuff covered as part of the “main” plot earlier.
HP Lovecraft, as I recall, would do something similar too - talking about Terrors From Beyond that were far, far too terrifying to describe to mere mortals, but trust him, they were pretty terrifying.
They’re not the only examples, of course - but it does seem to pop up rather a lot in that time period. It’s also a bit jarring and seems to me, as a modern reader, not unlike a James Bond novel consisting of a detailed description of the paperwork 007 has to do as part of his jobs, the complicated political intrigues he must engage in to secure a plum assignment investigating an upmarket and exclusive brothel in Monaco being used as a front for something, then glossing over the entire mission and adventures there to conclude with an exhausted and slightly gunshot wounded Bond returning to his office and finding his expenses claim as been rejected until he goes downstairs and sorts it out with itemised receipts, perhaps a few judicious swear words and maybe some judo throws for good measure.
I’m not including the Sherlock Holmes-style convention of alluding to other adventures the characters have had which aren’t fleshed out (“Why look Watson, a hedgehog not entirely unlike the one who proved to be Moriarty’s undoing in the Mystery of the Ruptured Duck!”) in this question, though, but more focusing on “Cool stuff which the author fast-forwards through”.
So, to get back to the point: is there a (serious) name for the 1880s-1920s literary device where the author spends a lot of time on seemingly irrelevant or not necessarily exciting stuff and then “fast forwards” through potentially interesting or exciting stuff with a handwave/glossy coat of moving right along?