According to a new report by research firm Canalys, in the first quarter of 2011 Apple grabbed 74% of the worldwide tablet market. Canalys is the first firm to include tablets and, more specifically, the iPad in total PC shipments, and as the PC market grew 7% overall in Q1, the research group notes how the most impressive growth was reported by Apple.

Taking into consideration the iPad’s ‘halo effect’ on the company’s other products, Apple has grown considerably in most markets worldwide,’ said Canalys Analyst Tim Coulling. ‘As the iPad 2 and its competitors continue to roll out, we expect pad sales to propel PC market growth for the rest of the year.

Apple continued with its strategy to dominate the pad market, with the iPad or iPad 2 available in 59 markets by the end of Q1. A combination of strong Q4 sales and the announcement of the iPad 2’s launch across major markets at the end of March contributed to Apple’s iPad shipments being down 31% sequentially. The full impact of the iPad 2 launch will not register until subsequent quarters, as Apple gets the product into the hands of consumers.

Apple positioned #4 in worldwide total PC shipments behind HP, Acer and Dell, shipping 8.5 million computers & tablets in Q1, as opposed to 2.9 million Mac shipments in the year-ago quarter. Whilst Dell was the only PC vendor of the three ahead of Apple to post positive growth in the quarter with a 2.8% increase, Apple reported a 187.9% growth with Macs and iPads combined.  Canalys notes tablet shipments reached 6.4 million units in the quarter, with Apple grabbing 74% of the market. In their Q2 2011 earnings call for the quarter that ended on March 26th, Apple posted record revenue of $24.67 billion with 4.69 million iPads and 3.76 million Macs sold. iPad shipments are expected to grow in Apple’s Q3 as suppliers recover from the Japanese disaster and are able to meet demand of tablet components such as LCD displays and RAM.