Deleting Columns or Rows
Before you delete a column or row, delete the apps or gadgets in the column(s) or row(s). Mashboard deletes columns from the right and rows from the bottom.
Note: If an app or gadget is spanned across a column or row to be deleted, you do not have to delete the app or gadget before hand. Deleting the column or row simply updates spanning properties to account for the lost cell(s).
Then click Column Layout or Table Layout and change how many columns or rows are selected.