It appears that the A and B values and the different columns of times are for different dilutions of the concentrate. The first column is for one part developer to ten parts water, the second for one to twenty, and the third for one to thirty.
Within each dilution column is the recommended number of 3-second inversions for each agitation cycle (under A) and the total development time (under B). As I read it, if you're developing FP4+ in the 1+10 dilution, you should develop for 8 minutes (at 20 C) with 5 agitations (taking 3 seconds each) at the top of each minute (most instructors would recommend continuous agitation for the first 30 or 60 seconds after pouring in the developer, however).
It's uncommon to see this agitation rhythm specified by film type and dilution for a developer; most (like D-76 or ID-11) separately specify a manufacturer recommended agitation method (like Ilford's 30 seconds on fill and two or three inversions every 30 seconds) and vary only the total time by film -- though some workers do claim that varying agitation changes the quality of development in some ways.