Yes - but do you have a Roshan microSIM? If you have a regular SIM you'll need to cut it down to size (really) by trimming off the excess plastic so that it will fit into the microSIM slot in the iPad. Because only the iPhone4 and the iPad use microSIMs there are not so many around. You can purchase quite cheaply from Amazon a microSIM cutter - it's a sort of guillotine device into which you place a regular SIM, press down the guillotine and it cuts off the excess plastic precisely. The advantage of using one of these devices (you'll find lots of instructions on the Internet about how to do this with a pair of scissors) is that the cutter comes with an adaptor so that you can turn it back into a regular SIM later on, if you have to.
Tim