There are two types of shapes in diagrams.net where you can add new rows.
- ERD tables use the new extended table tools in the Arrange tab of the format panel.
- Simpler text lists and UML class shapes use the row shapes to add new rows.
Add a row to a table or ERD table shape
- Select the table and click a second time to select a cell.
- In the Arrange tab of the format panel, click the Insert Row After or the Insert Row Above button. If you had selected the entire table shape, a blank row will be inserted at the end or at the start of your table, otherwise it will be inserted before or after the selected cell.
Add a row to a list or UML class shape
- Drag a List Item shape from the Entity Relation shape library and drop it over your list shape to insert a new entry.
- Drag an Item shape from the UML shape library and drop it over your class shape to insert a new attribute or method.
Use a keyboard shortcut to add a row
Alternatively, you can highlight a row and press Ctrl+Enter on Windows or Cmd+Enter on macOS to insert a copy of the row directly below in either the new table shapes or the older list shapes.