There are two ways in which you may transfer your RoboForm data from one Mac to another.
1) Make a copy of your Logins folder using Finder. The Logins folder is a RoboForm Profile and it resides in Documents folder. Install RoboForm on the other Mac >> move the folder to the Documents folder of that Mac (overwriting the contents of that folder).
2) Use your RoboForm Everywhere account. Install RoboForm on your new/secondary mac and sync your account using the same login credentials you use/used on your primary mac.
Upon doing so, it should populate your RoboForm Profile with all its data.