For detailed information on setting up Table Rate Shipping in Magento please follow instructions provided in this article or the following quick video tutorial:
The import tool for table rates is located at System > Configuration > Shipping Methods menu in Magento Admin area, to access it you can use the following steps:
- select "System > Configuration" option from the top menu
- change configuration scope to "Main Website" at the top of left menu
- select "Shipping Methods" from the left menu
- expand Table Rates section
