Fields and Tables are some of the most useful types of code one can use in WinCUPL. It essentially allows you to build a truth table, and have the PLD function as your software specifies.
The application of this type of code falls under combinational logic, and is quite different from the other types of applications that one may need to use. But it is a valuable tool when building any type of logic equation that is to do some type of decoding.
The video below gives a brief example of how to use Fields and Tables as well as providing source for the examples used.