I'm an Android guy (Samsung phones), but I got an Amazon Fire 8" tablet at a yard sale for $10. It was just the right size to hold in one hand, good battery life, took a micro SD memory card, fast enough for simple things. BUT it was limited to what apps Amazon provided. I did find a non-Amazon book reader called e-Library Manager Basic, that worked well, and as mentioned, I downloaded Libby (and it came with Kindle). I put all my books on the memory card, figured how to load them into my ebook reader, and I used for reading on trips for a couple of years. It worked well for that. But I wanted to do all the things I do with my Android phone. Best deal I found was on Walmart's website, a TCL 8SE tablet. 8" screen, memory card slot, fast processor, ran Android 13 (pretty new). It was only $68 as an open box item, normal price was $99. AND it had an unlocked cellphone radio! So I put in a $3/month Ultramobile sim card, and now I can even communicate with it. Since it's Android, I just downloaded all the same apps that are on my phone, and I can really do everything on both devices. I use my "normal" web browser, email program, "contacts" app, Google Voice, Organic Maps, etc...
Added note: I replaced the sim card with an esim adapter card from 5Ber ($25), downloaded their Android esim app, and now I use inexpensive esims on the TCL tablet.
If you are an Apple person, maybe best to stay in the Apple world, but I'm real happy with my TCL tablet for reading and traveling.