Apple shipped the most tablets during the second quarter of 2014 (13.3 million), despite selling 9% fewer units than it did during Q2 of 2013. Apple's market share decreased 7.1% year-over-year -according to data from IDC - but the Cupertino, Calif.-based company maintains its market share lead with approximately 27% of overall tablets sold worldwide.

During the second quarter of 2014, 49.3 million tablets were shipped worldwide, an increase of 11% compared with the same quarter in 2013.

Samsung sold 8.5 million tablets in the world during the quarter. Samsung's market share also slipped, down 1.6%, compared with last year. However, the company holds 17.2% of the current market share. This month, Samsung released the Samsung Galaxy Tab S, a 10.5-inch and 8.4-inch tablet that is 0.9mm thinner than the iPad Air.

Lenovo and ASUS neck-and-neck

Lenovo and ASUS held the third and fourth spots in the rankings, having sold 2.4 and 2.3 million units, respectively. Lenovo holds a 4.9% market share and ASUS is slightly behind at 4.6%. Lenovo witnessed the greatest year-over-year growth during the quarter, having sold 64.7% more units than it did during Q2 2013.

In April, Lenovo unveiled revamped A-Series 7-, 8- and 10.1-inch tablets. Asus teased the Asus Transformer Book V in June. The new device is an Android laptop that can transform into a tablet and a phone.

Acer sold 1 million units during the quarter, which was good enough for a 2% market share. However, the company sold 36.3% fewer tablets than it did during Q2 of last year. In May, Acer announced the Iconia Tab 8, a Wi-Fi-only tablet with an 8-inch 1920 x 1200 anti-fingerprint display.