General :: Prevent Export Of Table

I have set up a database that each user will put on their own computer, as it builds a running list made specifically for that user of chosen items to be exported to Excel, and because the remote locations have issues when accessing a shared network.

The db verifies the network user ID against a table to allow it to open. This to prevent any unauthorized user from accessing, and if db was copied or forwarded, only authorized users could see the data.

If the user is not on the list, it advises "Not an Authorized User", then exits Access. (I disabled the shift on opening, hid navigation bar, etc.) When further testing this security, I realized that even though users can access only the forms that I allowed, if they were to open another Access db, they could link or import the main table.

So all of my security precautions are for naught, as anyone with access to the db could see the confidential data. Even if they were not valid users, they could still get to the data if they knew how to import from another db. Is there any way to lock down the main table, so that it cannot be exported? Or be imported into another database?