Before you import your table rate CSV, make sure you have correctly configured it using the how to set up shipping table rates guide.
From the System->Configuration page, select Sales-Shipping Methods from the left hand navigation and open the Table Rates section.
In the upper left corner, set Current Configuration Scope to the website where this method will be used
Next to the Import field, click the Choose File button. Select your completed CSV file, and import the rates.
Import Table Rates
When complete, click the Save Config button. Then, go through the payment process with different addresses to make sure the shipping and handling rates are correct