The dimples are called kullenschiff or just kullens. Their purpose is to prevent wet food from sticking to the blade. They trap air inside and prevent a vacuum from forming. Kullens are only effective when slicing something large enough so a slice will cover at least two. Kullens are good for coining cucumbers, and carrots, helpful for slicing soft meats and hard cheeses -- things like that.
Very few knives with kullenschiff can do a good job on soft cheese, foie gras, or a number of other products that are just too soft and wet for them. Kullens won't keep chopped and minced food from sticking -- too small.
Almost all knives with kullens are made for right handed users -- and the function is completely wasted on lefties. MACs are included in this group. Some kullen designs aren't particularly helpful, some work very well. MAC's kullens do work fairly well. Glestain's are by far the best. They are, in fact, so sick they're stanky. You have to ask yourself, "How much cucumber do I slice? How annoyed am I at its hanging on to the blade?" If the answer to either or both of these questions is "Not all that much, really," get the MBK-85. BTW, those MACs are great knives. Not flawless, but a lot of performance for the money.
Use it in good health,