Recently I had a need to transfer about 100 gigabytes of files across from my iPad to my Mac. iCloud Drive and USBs were too slow, and AirDrop wasn't very stable. So here's a trick to share them over SMB.
Connect the iPad and Mac with a USB cable and enable "Internet Sharing" from the Mac to the iPad. This is to create a wired ethernet connection between the two devices. Next enable "File Sharing" to create enable the SMB server.
From the Files app on the iPad, connect to your Mac's SMB server, and copy the files across!