Unless the finder has the device Passcode, it won't be possible for the finder to access the iPad or any information stored thereon.
There are only a limited number of attempts to enter the correct Passcode before the iPad will be automatically disabled - after which the iPad will be useless until restored. As such, repeated attempts to guess the Passcode will cause all locally stored data to be permanently beyond reach.
If attempts are made to restore the iPad, the device itself will remain useless to the finder - as the iPad will still be Activation Locked. Unless your AppleID credentials are known to the finder, the iPad cannot be reused by anyone other than you.
Additional information
Locate a device in Find My on iPad - Apple Support
Here is Apple’s advice for lost or stolen devices:
If your iPhone, iPad or iPod touch is lost or stolen – Apple Support
Use the Find My app to locate a lost or stolen device – Apple Support
If the Find My iPad feature was enabled prior to it being “misplaced”, then if active, you would stand a good chance of locating it.
However, if the feature was not activated prior to being misplaced - or the iPad has been inactive or without a network connection for more than 24 hours, the last known location will not be available - and the opportunity to use technical means to recover or remotely managed the iPad may have been lost.