For those of you a little deeper into networking, I have taken an additional step to prevent the updates on my home network. I use pihole on my home network for DNS. I've taken the DNS entries from the Amzn_Blklst.txt and manually added them to the blacklist of the pihole. This prevents access to the amazon update servers completely, and you don't need to worry about rebooting the tablet and DNS66 not loading in time. It has the added benefit of blocking updates to other amazon devices on your network as well.
I'm gonna have to get me a Pi. I think they're still under $50.
Edit: No, wait! I've already got a single board computer that sits idle most of the day. It's the Odroid XU4 that serves up all my media files on my network. I could put PiHole on that and not spend a cent!