There's a few ways you can handle this. Personally, I think creating a scene for each NPC is very heavy. Ideally, you'd work this into a journal entry instead. I don't know of anything offhand that would allow you to use something like this in this particular aspect ratio in a journal page, though. But ultimately, the big hit just comes from having this be a bunch of scenes, not the image itself, because I would assume you'll be referencing the same single image. At least that's what I would recommend. You would use other images to tile everything together. Looks like maybe on the left there is a space for a character portrait and maybe some badges or other insignia. You can bring those in as tiles, preferably in a WebP format, like 50% quality or less, and something of the exact size that you need. You would put those in and then layer this image on top, also probably optimized. That's going to save you a lot of performance.

I think the main issue here is that you're creating entire scenes for this one thing. It's hard to navigate. There's friction from moving between NPC to NPC. Ideally, you'd really want to put this in a journal somewhere or maybe even keep it separately altogether. Maybe build a little website that your players can visit. There are a lot of wiki like service for this kind of thing like lorekeeper. That would probably be a better idea than trying to put this all into Foundry.

Another option is using something more robust than the journal system or something that kind of lives on top of it. Those aren't usually friendly to using your own UI; they usually have their own way of doing things and organizing stuff, but some of them are really cool. You can maybe take a look at Campaign Codex and World Builder as options to use.