K, I think you're using the table wrong. That table has absolutely nothing to do with actual lighting you ought to install.
The table is in the part of the code that discussed "load calculations." This same area also defines panels as one of two types (power or lighting). By "lighting load" they are referring to the basic minimum electrical service that ought to be supplied to an area. The different occupancies listed are more of a guide, than actual code distinctions; a wise designer will likely break up an area into several different 'occupancies' for these calculations - even if there are no walls!
This "lighting load" is but a starting point. The same section of the code includes methods to calculate loads for receptacles and specific appliances or areas. These figures, added to the 'per sq. ft.' figures, gives you the minimum service size.
This is completely different from calculating how much light you need, and where that light should be located. For example, you'll want a lot more light over a work bench or aisle, than over the tops of the pallet racks. In those calculations, you will typically be using lumens, or candlepower .... not watts.
As for watts vs. volt-amps, for all intents and purposes they are the same thing. The difference only becomes relevant in discussions of power quality. Simply put, loads with large impedances (motors, transformers) or lots of electronics (ballasts, frequency drives) change the waveform from a nice, smooth sine wave to something else ... fooling you meter into thinking they are using less power than they really are.
Load calculations are a basic part of traditional electrical apprentice training programs. They are not, generally speaking, ever mentioned in the training of an industrial electrician. The industrial guy's training is focused on the equipment, rather than the building. It is certain that the industrial guy deals a great deal with motors and controls - but he can still go his entire career without ever seeing a GFCI or pulling a meter.
