Save for a few legacy projects that still use Fusion Tables I don't actively use this script anymore. This update hopefully solves the OAuth issue that cropped up once Google depcricated the Client Login method used by the prior version.
As always, your mileage may vary, and I welcome someone -- Google or otherwise -- to offer a long-term maintained solution.
The following is largely cribbed from a Google example here. I try to explain some of the API settings that must be enabled in the Developer's Console and elsewhere