Solar Panel Energy

Can the 5kw Luxpower Off-Grid Inverter use PV & Grid to take the load, like a hybrid inverter?

Yes, for example, if the battery is fully charged and the hybrid function is selected, the inverter will direct the incoming power from the MPPT to take the load and import the balance from GRID.
When your solar is limited (night/cloudy), the grid (if available) can step out to make up and meet the loads need, this is a great advantage comparing to other off-grid products where you are stuck with solar and battery only.