The Table Designer is a visual tool allowing you to design and visualize a single table in a database to which you are connected.
The Table Designer has two parts. The upper part shows a grid; each row of the grid describes one database column. For each database column, the grid displays its fundamental characteristics: column name, data type, length, and nulls-allowed setting.
The lower portion of the Table Designer shows additional characteristics for whichever data column is highlighted in the upper portion.
From the Table Designer, you can also access property pages through which you can create and modify relationships, constraints, indexes, and keys for the table.