When you need to adjust the daily rates charged to an existing booking without affecting the rates in your setup.
This would happen if you offer a one-time discount on a booking and you need to manually capture the daily rate.
Click on the first cell with the current rate
Type in the new rate over the existing rate
If you want to charge the same new rate for the rest of the nights booked, click on fill to the right
The rates charged for the remaining nights of the booking will be updated accordingly with the same new rate.
At this point the booking total would have updated.