Any line that starts with | sign is a table row:
 
|Company|Address|Size
 
Company
Address
Size
Google
10,000
Yahoo
1,000
 
The easiest way to add a table is by using append menu:
tables.png
 
You don't need to enter table contents manually using | signs, you can just add the very first row of columns, then | sign will be added automatically. You can enter just the first column, then edit others dynamically.
 
You can sort/add/delete/rename/resize/move columns from the column menu:
table-column-menu.png