More than likely, because Windows formatted the drive in a proprietary format, rather than, in an open format. Besides that, check the drive is powered (not by the tablet) and adaptors usually keep the data lanes, but a lot don't keep the power lanes correctly (check if you can charge your phone, using the adaptors, if it charges at its highest, it isn't the adaptors)
If both are correct, then load file Explorer, or (preferably FS Explorer) this allows you to read different file systems, it'll be read only, if this is the case, and knowing that, you could easily change the formatting of the drive with your normal computer, ntfs would allow Windows and Android read/write access.
Oh, check first with your computer what attributes you have applied to the drive. It might be locked to your windows machine, showing no read access to anything else (depending on the drive,)
Actually all the rest would have to do with what type of hard drive us it... PCIe, sata, NVMe, sdd etc. And how old it is. Unless you know it's running it's own latest firmware, and what that firmware was built for. Which may be specifically for Windows.
Mind you, it's been about 5 years since I did this, and last time used Windows, with android basically running on a stripped back Linux kernel. I just decided to stay with it. Leaves things like this behind, but running Linux, makes these things easier. but making things work on it, that were built for windows can become extremely difficult. Which is where a virtual machine comes in. If you haven't heard these words before, don't worry, as much as I love it. It isn't good for intuitive learning, it's allot more useful if you know how to code already, or work from the CLI quicker than you could with a GUI.
(E.G C++ is completely Integrated.)
Sorry about the tangent at the end
