If a named area consists of multiple rows or columns, to resize it, select rows or columns inside the area and then, on the main menu, point to Table, point to Cells and click Insert.
If an area consists of a single row or column, it cannot be expanded. You can remove the name and assign it to a bigger area instead.
To reduce the size of a named area, select rows or columns to be deleted, right-click them and click Delete.
You can do the same for rectangular areas. If you select individual cells instead of rows or columns, the area cannot be resized.
Next page: Managing spreadsheet document groups