I'm a huge advocate of switching entirely to tablet if possible. I've done this for my own meager music library, and actually made the ultimate commitment - I've retired my music desk completely and just have the tablet mounted to a dedicated holder on the plate:
I don't know the best way to handle large anthologies on paper though, breaking the binding and scanning all those sheets would be a huge pain that I feel probably isn't worth it. I suspect a copy shop might be able to do the scanning for you? They definitely can chop the spine to spiral-bind it (something I've done before too).
But if you're really just spending a few minutes to sight-read, I presume you're not committing to the piece. In that case, just keep using the paper book. If you find a piece you really like, you can photograph/scan it and use it in your preferred sheet music reader, and you can save those digitally for posterity.
Like @thepianoplayer416 and @WieWaldi I also use PDF format, and I use MobileSheets Pro as my reader, mainly because it supports nearly everything--cropping, repagination, annotation, synced multiple tablets, multi-platform (windows/android/chrome/ios) support and syncing, bt/remote page turning, has local, cloud and local-network backup options, AND it even supports intent triggers so I can work Mobilesheets into my dumb home automations š