To Rotate a Table 90 Degrees
1. Select a table.
2. On the Table tab, in the Table group, click 
Rotate. The table rotates by 90 degrees counterclockwise about its origin. Each time that you click this command, the table rotates an additional 90 degrees.
Rotate. The table rotates by 90 degrees counterclockwise about its origin. Each time that you click this command, the table rotates an additional 90 degrees.Alternatively,
1. Select a table.
2. Right-click and click Rotate on the shortcut menu. The table rotates by 90 degrees counterclockwise about its origin.