If you connect the tablet via USB, there's a toggle in the settings which lets you access the tablet from a web browser. It allows you to copy stuff to and from the tablet.
It works on my work laptop which has the USB ports locked down for data - I can normally plug in the items approved for work like my printer, hearing aid programmers, video otoscope etc but it doesn't allow me to use non-Bitlockered USB drives. The tablet doesn't show as a storage device like you'd normally expect and uses some kind of black magic fuckery to transfer data.
You can also use OneDrive to download stuff to the tablet, but I don't think you can go the other way and upload anything to the cloud. My workaround is to simply email any marked up documents to myself.