The main reason for this size of a smartphone so big is for for "extensive viewing multimedia, web browsing, and more.” It's called a smartphone with extensive viewing features.
The Galaxy Mega features a 5.8" HD LCD or 5.8" QHD screen, and familiar Samsung Galaxy software features including Group Play, WatchOn TV remote, Samsung Link (for streaming), S Translator, ChatOn, S Memo, S Planner, S Travel, Story Album and Air View.
These huge phablets run Android 4.2 Jelly Bean, dual-core processors, 8/16GB internal storage, 8MP camera, front cameras, 1.5GB of RAM and microSD slot.
The Mega 6.3" runs a 1.7GHz dual-core processor, difference GB of storage and 3200mAh battery while the mini Mega at 5.8" has a 1.4GHz dual core processor, 8GB of storage and 2600mAh battery. The Galaxy Mega models will be release starting in May in Europe and Russia.