I think yes, but tech critics and industry researchers have different methods of defining a PC and counting the numbers. T.T. O’Brien explains:
No one would argue that a Windows personal computer is not a PC. Ditto for the Mac. In fact, we have a predisposed bias to what constitutes the definition of a personal computer and tablets don’t fit into that category.
Should they? Wikipedia’s definition:
A personal computer (PC) is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use. PCs are intended to be operated directly by an end user, rather than by a computer expert or technician.
iPad is a PC. That makes Apple the largest PC maker. Imagine that.