Choosing a wall tablet

These are suggestions based on what people commonly use for this kind of thing. We haven't tested them, there are no affiliate links here, and prices change — check before you buy.

What matters, before any model

10 inches or larger. It's read from across a kitchen, not held.
LCD, not OLED. A wall display shows a near-static image all day, and OLED risks burn-in. Every tablet below is LCD, which is one reason to stick to the cheap end.
Permanent power is the real problem, not the tablet. A tablet held at 100% charge day and night will swell its battery within a year or two — this is the most common way these setups fail. Fully Kiosk Browser can hold the charge between limits, roughly 20–80%. If you're not using it, put the charger on a smart plug and cycle it.
Think about the cable before you mount anything — a socket behind the tablet, or trunking down to one.
Android is easier than an iPad for this, because Fully Kiosk Browser does everything you need and iOS Guided Access doesn't.

Suggested devices

Samsung Galaxy Tab A9+ — 11 inch, LCD
The sensible default. Full Google Play, so Fully Kiosk installs normally, a decent screen and solid build. Around £150–200.
Lenovo Tab M11 or M10 Plus — 10.6–11 inch, LCD
The best screen of the group, which helps a layout with several cards on it. Around £150–200.
Amazon Fire HD 10 — 10.1 inch, LCD
Cheapest by some way, often under £100 in a sale. The catch: Fire OS has no Google Play, so Fully Kiosk has to be sideloaded, and you'll want to turn off the lock-screen adverts. Fine if you don't mind a fiddly evening.
An old iPad you already own
Free, and it works using Guided Access — but more restrictive than Android, with no Fully Kiosk equivalent. Worth trying before buying anything.

On mounting: magnetic and adhesive wall mounts exist for most of these, and a recessed in-wall mount looks best if you're willing to cut plasterboard. We don't recommend a particular seller.

Setting it up

Mount it somewhere with power.
Install Fully Kiosk Browser — or turn on Guided Access on an iPad.
Set the start address to:https://kerfuffle.family/wall
Pair it from Settings → Wall tablet.
Turn on the screensaver and night dimming.
Set the charge limits, or put the plug on a timer.