Hi Hock, you can add columns to the any report, including hostname column to Top XX Endpoints report. Just edit Top 50 Endpoints - Last 24 Hours report, then in 'Custom table' click on 'Edit table'. This will redirect you to page where you can specify columns displayed in report so just add Hostname column to that report.
I recommend reading:
Hope this helped,
thanks, Stibi. But I am referring more to the real time netflow reports rather than the report writer.