This is the engine room of the TIM system, and gives remarkable flexibility for administering how your calls are costed. They look quite complicated at first, but looking a little deeper, things soon make sense.
Collectively, the pricing and dial code information is known as a tariff table, and such a table exists for each network carrier. In some cases, a single network carrier may have more than one tariff table to cater for its wide-ranging pricing structures. Each table can be edited separately, thus allowing complete flexibility in how the system costs your calls.