Just an observation from way too many zoom meetings: It seems that whether or not one is automatically reconnected to the meeting correlates with the duration of the network disruption, the magic threshold seems to be around 10 seconds or so

Maybe a wired connection would be more stable? There are LAN-to-USB connectors or docking stations which might allow you to hook your tablet to a wired connection (I'm not an Android user, so no actual data how good that works)

I'm not sure if this is something the host can configure, but in a conference which ran for 3 days straight (people from different time zones would join at different times for the talks), the meeting was interrupted by zoom about every 24 hours and people had to rejoin. Maybe that's something for your host to keep in mind and not start the meeting too early.

Is using voice control allowed? Or training your cat/dog/parrot/... to press the buttons for you?

Voice would be less bad than direct touch, but automation would still be better. (The issue is avoiding computer use (and other electronics) on Shabbat.) The cat would be better too, but cats aren't known for doing what you want them to do. :-)

When I join the meeting, I get a "waiting for the host to start the meeting" message and then when I return to it later the meeting is in progress. So I think the host isn't starting it that far in advance and I'm queuing up via the meeting URL. Fortunately, the URL embeds the password, so I don't have to get past a password prompt on Shabbat.

When the connection dropped on me yesterday I was just sitting there, not walking around with the tablet or anything like that. I'll look for tablet-compatible ethernet adapters.

When I join the meeting, I get a "waiting for the host to start the meeting" message and then when I return to it later the meeting is in progress.

That's good. So you are in the waiting room before, which means that you probably don't have to worry about the daily disconnections from the server side.