"Wi-Fi only" means that the device only has Wi-Fi and does not support a mobile connection (e.g. 4G or 5G). This means that the Galaxy Tab S6 Lite (2022) can only be connected to the Internet via a Wi-Fi network and has no SIM card or mobile data connection.
No. There's no fingerprint reader. There is facial recognition, but from my point of view, it doesn't work very well: very often, the tablet doesn't recognise my face (but I haven't tried redoing the procedure), at least for unlocking. Facial recognition on phones (tested on iphone, galaxy and fairphone) works infinitely better.
The Samsung Galaxy Tab S6 Lite 2022 does not have a fingerprint reader. However, it does feature facial recognition and password protection to secure access to applications, including online banking.