Super. With Handbrake the DVD should be visible in the sources list. Or you can transcode the mkv you did already backup.
My guess would be that for your device you need one of the Apple presets, probably
Apple 1080p30 Surround. For my tablets, since mine are older and their processor is weak, I also check
Fast Decode.
I marked the settings in red. Give it a try and if needed adjust from there.
I will also add this link
https://www.howtogeek.com/102886/how-to-decrypt-dvds-with-hardbrake-so-you-can-rip-them/If the DVD is not protected you don't need all those steps (you don't need libdvdcss), but for the first time user they do explain better what to click.
You'll obtain an mp4 or m4v (you can force the extension in settings if you want to, I always keep mp4) and you'll have to transfer to your table with ITunes or similar (on my old ipad mini I have ITransfer which can retrieve files from my network/NAS and it's the only mean of transfer I've ever used with apple).