operator information can be placed into csv file and load the file through listener. call the OOTB activity Data-Admin-Operator-ID.CreateOperator (passing the required parameter values) from the service file activity.
If not through File listner , you can have a control in UI : "FilePath" on click of which you need to select a CSV file.
After the file has been chosen You need to run post activity where you have to set the file path, then you need to parse the file, and create the page list in clipboard, after that you need to compare the same with model operator and create the same .
I would like to understand why you want 7k operator to be created in one go, because if you are sso they should be created at login through Authentication service and other option I can suggest is register in order to create your operator by providing basic details that can be either using guest user/unauthenticated user provide basic details and register.