Table Editor screen

Selecting Columns, Rows and Cells

You can select rows and columns by clicking on their header cells (leftmost column for selecting rows, topmost row for columns). You can select multiple rows and columns with Ctrl + click.

To select a range of cells (as opposed to a set of rows or columns), click on a cell and hold until the cell is highlighted. Move the cursor while still holding down the mouse button to select adjacent cells.

Removing Rows and Columns

Select Delete Row or Delete Column to remove all the selected rows or columns.

Adding New Rows and Columns

Select Add to add a new row or column. By default, Add will prompt you to select references to include in the new cells, but you can also choose to add empty rows or columns. If you switch to adding empty cells then that will remain the default action for Add until you re-open the Table Editor.

Add references...

If you have selected a row, you are presented with a dialog that lets you select objects, either from a browser or from the clipboard. After selecting Next, the second dialog lets you reorder those objects. 
The third dialog lets you select attributes of the objects you have chosen. The final dialog lets you reorder the attributes.
One row will be created for each object you selected, and the cells of the new rows will contain references to the attributes you chose.

If you have selected a column, the same four dialogs are presented to you, but you select attributes first and objects second.

Add empty rows/columns...

Select the number of rows or columns to add, and whether to insert them before or or after the current selection point.

If the table is empty, select both the number of rows and columns to add.

Creating and Destroying Straddles

A straddle is formed from a rectangular block of contiguous cells. Select  (Straddle) to merge selected cells into a single, larger cell, whose content matches the top left merged cell. you can merge an existing straddle with neighbouring cells and straddles.

If you select a single straddle, then  changes to  (Unstraddle). This reinstates the cells that were previously merged to form it. They will be empty apart from the top left cell, which will have the content of the straddle.

Editing cell content

Select the content of cells to edit it using the attribute editor.

Editing an Empty Table Attribute

When you select an empty instance of a table attribute you can choose to create a new table based on a Table Style or to build the table manually, using the Table Editor.

When the Table Editor opens for an empty table attribute it shows this image:

Add is enabled, and selecting it opens the Add Rows dialog by default. From then on, the process is identical to adding rows to an existing table.

You can also choose to create a table from a file with the Import from file... option. Select a CSV file to create a table. The content of the table's cells will be unreferenced text.