Default Rate Tables - P1302

Folks,

I am somewhat confused as to the reasoning behind multiple Table options in the P1302. I can understand the need to create multiple tables in teh event I want to bill the same piece of equipment to a different Job at a different rate:

eg: Rate Table 1 - Dozer - Bill 100/ hr

     Rate Table 2 - Same Dozer but bill 150/hr.

So Job ABC uses Table 1 and bills that Job 100/hr.

Job XYZ uses Table 2 - and bills that Job 150/hr.

That's all good but why do I need to have the flexibility to enter up to 5 tables in the P1302? Is it purely down to the preference of managing the table entries in smaller files? Please try and give a real world example rather than a reference to implementation guide blurb. What conditions would need to be present for me to have to enter more than one Table for a Job? Unless, for some reason I've had to break up the table build into smaller tables to get the right mix of billing.