CThe key shortcut Ctl+Shift+Insert should insert a new row in the Query Columns component of Design view. This shortcut is indicated on the right-click menu. Reproducible: Always Steps to Reproduce: 1. Open a Query 2. Move into Design mode 3. Use the mouse to position yourself in the middle of the Query Columns area 4. Press Ctl+Shift+Insert Actual Results: Nothing happens Expected Results: A new blank line to be inserted. Similar issue with a Table, but I have done a separate bug for this. The function does work from the right-click menu.
Fixed in git commit d1a760f76596306e2a2651 for bug #338832 as it's in fact the same bug.