Enter description for Packlist directly on the line

We do a lot of miscellaneous "Other Shipments" packlists. Every line needs to entered in the box provided for "Shipment Description" and it is then populated in the list below. It would be quick to be able to enter and edit the text right on the line (just like a purchase order line), for both description and quantity.

So in short, enable text to be entered in the highlighted part in the picture attached.