One who is a master at performing tasks; is known to perform tasks well- multiply at a time. They are great and not everyone can achieve the level of the task master. Becoming a task master means being disciplined and focused.
girl: hey that boy over there is a task master! did you see the way he paid the clerk, answered his cell phone, and threw away his trash all at the same time?
boy: nothing like my friend at work who works on the computer, does filing, keeps track of inventory and answers the phone all at once.
girl: oh, guess your friend really is a task master!