Can you use AWS Snowball for local data transfers without importing the data to Amazon S3?

Yes, provided you're not crossing international borders, you can set up the job as a local compute and storage only job and use an AWS Snowball Edge device to move the data from one location to another. No data will be imported to Amazon S3.

Note: When using an AWS Snowball Edge device for a local compute and storage job, it's a best practice to remove the data from the device before returning it to AWS. The device will also be erased following National Institute of Standards and Technology (NIST) 800-88 standards when it is returned to AWS.