It used to be that the keyboards were alphabetical, but typists would get to fast and break the keyboards. They decided something had to be done, so they re-arranged the keyboard and came up with the "QWERTY", I believe it's called.
" The first commercially successful typewriter was developed by Christopher Latham Sholes in 1873. Originally, the keys were arranged alphabetically. However, a problem soon arose. People became so adept at using the keyboard that the keys would stick or jam when struck in quick succession. In order to overcome this problem Sholes decided to make the job of typing as slow as he possibly could. His solution? He placed the most frequently used keys as far apart from each other as he could. His keyboard became known as the QWERTY keyboard.
So, that is the reason why your keyboard is formatted the way it is. Ironic, really – considering that every other aspect of your computer is streamlined for maximum efficiency and yet you have to labor over a 127 year old system designed specifically for inefficiency. And inefficient it certainly is. For one thing, QWERTY was not designed for touch typing, which came much later. For keys that are not in the middle or home row it is necessary to reach across diagonally. This is difficult and leads to a high error rate.