I would have said that chalking over the table makes tables even dirtier than overchalking does.
Unfortunately there is no reason that both can't be done! Overchalking over the table is quite possible. One reason I refuse to build chalking into my preshot routine, I have seen people chalk three or four times when trying to decide what shot to take!
Snooker players often chalk between every shot but they only swipe the chalk across the tip once, not chalking the entire tip. I guess the entire tip gets chalked in the course of a frame or maybe they always hit the spot they chalk. Never watched close enough to see.
Hmmm, I just had a thought. There are cordless fish hook sharpeners that run off of batteries. A slight modification to hold chalk instead of a stone and I could market a cordless power chalker. That and a twenty dollar chalk cube and I could be rich by the end of a season!
Hu