This report will list all Vendors in your Blackpurl
From the Blackpurl Header > Reporting > Report - Vendor
The default columns and parameters is as per this screen shot
You can change your parameters are any time by clicking on 
or click on 
to select and/or deselect further columns
For further tips on reporting, please click on this link - Reporting Tips - Totals / Changing Columns / Changing Parameters / Exporting Search Results