I'm guessing the '19.4GB' is physical RAM + available virtual memory. If so, nothing remarkable. RAM usage in TM with everything closed is more or less what I'd expect from Win10 x64.
I'm not sure what to suggest, apart from cutting back on your tab habit. Some aspects of my Chrome configuration may help, such as setting Flash so it is only enabled when the user requires it and/or as per a site whitelist. I also have 'disable HTML5 autoplay' which is mostly to stop irritating auto-playing videos but I wonder whether it also cuts back on resource usage. I also have ublock origin.
I don't think I've ever seen my apps usage go beyond 4GB RAM (excluding when I occasionally run a VM), but then my browser habit involves closing unnecessary windows and resurrecting anything needed later from bookmarks. I keep a 'dumping ground' bookmarks folder for stuff of temporary interest as well.