You can launch multiple SecureCRT sessions at once in several different ways.
Method 1: Hold down the CTRL key, select multiple sessions in the Session Manager, then right click to connect to all of the selected sessions at once.
Method 2: Create a folder in the Session Manager, and then put copies of each session into that folder. Press the Connect button to launch all of the sessions within the selected folder.
Method 3: Open Global Options to the Default Session category, select Use Auto Session and specify the sessions to launch automatically when SecureCRT starts.
Method 4 (Windows only): Hold down the CTRL key, select multiple sessions in the Session Manager, then right click and choose Create Desktop Shortcut. The shortcut launches all of the sessions together; the shortcut target uses a /S switch for each session launched.