Hi Gabriel,
The image in your post is a screenshot of the "Weighted Efficiency" section of the Inverter Help topic:
samrepo.nrelcloud.org/help/pv_inverter.htm
For the Inverter Datasheet option on the Inverter page, you can provide either the weighted efficiency (CEC or European) value from the data sheet, or the manufacturer (peak) efficiency value the data sheet.
The time series inverter efficiency on the Results page is the operating efficiency in each time step, and depends on the inverter load and temperature in each time step.
Best regards,
Paul.