There is a plugin for calibre ebook software which can generate an epub file from selected wiki articles. Last time I looked it worked fine.
Wikipedia
A place to share interesting articles from Wikipedia.
Rules:
- Only links to Wikipedia permitted
- Please stick to the format "Article Title (other descriptive text/editorialization)"
- Tick the NSFW box for submissions with inappropriate thumbnails
- On Casual Tuesdays, we allow submissions from wikis other than Wikipedia.
Recommended:
- Use the search box to see if someone has previously submitted an article. Some apps will also notify you if you are resubmitting an article previously shared on Lemmy.
If you can run Python code off GitHub on a computer, I've never used it, but this tool on GitHub purports to do that. Hasn't had any commits in the past three years:
https://github.com/jonbirge/briki
This one apparently lets one convert one or more WP articles to a .epub, and is getting commits:
I don't know of any epub format sources, but it is possible to set up a static copy of Wikipedia on a personal computer using Wiki Data Dumps and Kiwix. Mayhaps that could be a starting point for public access or conversion.
Not exactly what you asked for, but koreader can download and display Wikipedia articles on demand (on a long press of a word). A quick google search seems to indicate koreader supports some pocketbook reader.
For books, a manual method is to choose a book with the Wikisource Reader app
https://f-droid.org/packages/org.cis_india.wsreader/
Press Download button, and then view them in the Wikisource library tab, click the share-icon, and choose the Save Locally app
https://f-droid.org/packages/com.mateusrodcosta.apps.share2storage/