Create a csv file with the details of name/ip address of the device, display name and device type.
Click on Setting > Discovery to go to the Device Discovery page.
Select CSV File Import option.
Browse and load the CSV file.
Once it gets loaded, you can see field details, 'Configure fields from CSV file'.
The file is parsed and the headers are shown on the right hand side.
Once you see the headers for each row, you can map the required fields to the csv file.
Note: DeviceName/IP header is a must for CSV file and other header fields are optional.