How do I transfer with airdrop to my iPad without someone else getting it.

Correct. Unless you choose his phone from the list of devices (the circles), he cannot receive your passwords.

That said, what kind of passwords (In apps, for websites, etc.) are you transferring and how are they stored? If they are passwords to websites in safari, they should be kept in your iCloud Keychain and accessible across all devices connected to your Apple ID. I do not believe you can restore data from a backup without resetting the device and setting up from the backup.

If you are trying to transfer from one device to your iPad using airdrop, all you need to do is select the airdrop option when exporting from the original device and select the iPad from the list of devices that show up. As long as you only click on the iPad, no other nearby devices should be able to get what you are transferring.