Make sure the phone number you have them call is the current phone number you and/or your companion will be using. No family member in another state who can't pick it up for you.
You want to make it QUICK and EASY for someone to get it back to you. If you make it difficult, or someone has to go out of their way, or it's too time consuming, they will drop it off at Lost & Found of the nearest building to them. (They may have walked with it a ways as they were trying to figure out what to do. So, it may be in a building you were even in. Or they figure you will use the Find My feature and simply come to wherever they are.) If it goes to Lost & Found, it then goes in a box or on a shelf. If there is a main Lost & Found, it may make it's way there at the end of the day. Then it will be up to you to try and track it down there.
Also add a current photo of you or a copy of one on your phone, or something easy to describe to prove, once you open the tablet, that it really is yours.