10 X 8 means the table can contain up to 10 columns and 8 rows.
To insert the table:
Your table is inserted into your Word document with evenly spaces columns and rows.
Insert a Larger Table
You arent limited to inserting a 10 X 8 table.

it’s possible for you to easily insert a larger table into your document.
Insert a Table Using Your Keyboard
Here is a trick that not many people know about!
you could insert a table into your Word document using your keyboard.
To insert a table using your keyboard:
This creates a quick table with one row.