The tablet is looking for an Internet connection to verify the account details and you are the legitimate owner/user. Set a temporary unsecured open (public) port connection on your wifi router so the tablet can connect to the Internet without being blocked by your security settings in your router.
Once connection is established, you can reset the settings in your tablet to automatically log on to your wifi router. Don't forget to resecure or delete the open/public port on the router.
You may also be able to connect with a cable direct to one of the router ports. There should be instructions in the tablet manual.