Yes. In the Users tab, click the Add button if you just want to add users individually, but click Bulk Import if you want to add multiple users at the same time. Bulk Import is available when adding Gateway users as well as Domain (Active Directory) users.
Before using Bulk Import, the Administrator must first create the file to be imported which lists the e-mail addresses of the Gateway users to be added, or which lists the Active Directory domain user names (if adding Domain users). The file should be in .CSV or .TXT format. In addition, before using Bulk Import, you must first set up the Email/SMTP configuration, in the Settings tab (so that invitation e-mail can sent automatically to each one).
Unlike adding users individually, when you add users via Bulk Import they will have a status of Disabled by default. After import is completed, you can enable the desired users, again keeping in mind how many Seats you still have available for Enabled status in your license agreement.
For complete details and illustrations, please see Chapter 4 of the full Splashtop Center Administrator's Guide.