What is the "Home" feature of the Stepper Motor Driver IC (DRV8811)?
You will be getting the HOME pulse every 4 steps in full-step, or every 8, 16, or 32 steps in microstepping modes. In microstepping, the state table contains "values" for the current to be sent in each of the two windings to set the rotor in a particular position relative to the full step (which doesn't need a state table). IIRC this is the position with the highest holding torue.

The microstepping waveform vaguely resembles one period of a sinusoid; in the table you've posted last column shows the "position" or angle corresponding to the microstep on this sinusoid.