According to Gartner's data, slightly more than 195.4 million tablets supporting various operating systems were sold in 2013. Of those, Android powered about 121 million units, or about 62 percent. Meanwhile, iOS powered 70 million units, or about 36 percent. The other miniscule 2 percent apparently consisted of Microsoft devices, spanning Windows RT (like the Surface 2) or Windows 8.1 (as in the Surface Pro 2).
Despite this, it should be remembered that Android's strength is the variety of OEMs and form factors. No one single OEM yet challenges Apple in the tablet space (Samsung is atop the cell phone -- not just smartphone -- market). Apple pretty much created the tablet market in April of 2010 when it released the first iPad.
Taking that into account, who are the big players in tablets? Apple is the no. one single manufacturer of tablets, by far, with nearly double the shipments of second place Samsung with about 37 million devices shipped. Amazon.com reportedly sold just under 10 million Kindle Fires. The rest could be categorized as "Other."
That is to say, the rest of the market, about 60 million devices worth, is a scattering of tablets among various OEMs, including no-name brands that can be purchased for much less than an iPad or a Galaxy Tab.
Roberta Cozza, research director at Gartner, said in a statement:
In 2013, tablets became a mainstream phenomenon, with a vast choice of Android-based tablets being within the budget of mainstream consumers while still offering adequate specifications. As the Android tablet market becomes highly commoditized, in 2014, it will be critical for vendors to focus on device experience and meaningful technology and ecosystem value -— beyond just hardware and cost -- to ensure brand loyalty and improved margins.