That's honestly unlikely to currently be a thing, since pre-integral menu (and engine-side) it's all one big list with pages, but PR's welcome.
Granted, I personally prefer the current layout because I can just hotkey everything (though, judging by your mockup, that would still be possible, kinda like how Grey Goo does it) and I don't want the clutter, but as an option, again, PRs welcome. LuaUI/Widgets/gui_chili_integral_menu.lua is the best place to start, though there's a bunch of other config and included lua files that set up the menu.