Disclaimer: These steps are general. Ensure you follow instructions specific to your device and ROM.
Because we disabled Auto Reboot, your tablet is still in Download mode. Now:
Now that the tablet had TWRP, I needed the actual operating system.
You will need a Windows PC (or Linux/Mac), a reliable USB cable, and the following software:
You can do this before wiping (if files already on SD card) or after wiping using MTP:
Flashing custom firmware wipes everything. Use Samsung Smart Switch or manually copy photos, documents, and videos to your PC or an SD card.