Upgrade to iOS 4.2 or higher enhances iPad / iPad2 with multitasking – the ability to keep as many eligible apps running in background as it can hold in memory at one time and keeping all others in suspended state where they are frozen at where you last left off. In theory apps will be purged from the suspended state if the Apple tablet runs out of dedicated system memory. So it is iOS responsibility to chose the correct moment for memory cleaning. However, if you have any doubt about performance of your iPad /iPad 2 / iPad 3 / iPad mini / iPad 4 get rid off all unwanted apps sitting in background. To do this just follow steps below:
One more reason to keep the memory of your iconic tablet as clean as possible is to keep its battery from being drained early. Energy avid apps living in background (especially those ones that feed speakers) do not favor battery's life span.