To copy a table, click anywhere in the table. Then Click on the menu item Table, and click on the submenu item Select, and then pick Table from the list.
The whole table will be highlighted. You can copy by clicking on the menu item Edit and selecting copy, or by pressing the CTRL and C keys together (press CTRL first)
Move your cursor to the location you want to place the copy of the table and press CTRL and V to paste the table. You can use the menu item Edit and Paste to do the same thing.