With the "Update library elevation" feature, the library elevation is changed by selecting one of the elevations in the list.
Click the update library elevation command.
Select the object whose elevation you want to change and click the right mouse button to finalize the selection process.
The select entity dialog will open. Select the object you want to place on it and click the OK button.
The elevation of your object will change to fit on the object you selected from the list.
Before updating the coffee table elevation:
After updating the coffee table elevation: