There are keyboard layouts that do this. I'm not particularly knowledgeable about layouts optimized for English, but I use neo2. It's optimized for German (prim

There are keyboard layouts that do this. I'm not particularly knowledgeable about layouts optimized for English, but I use neo2. It's optimized for German (primary goal) and programming and English (secondary goals). It's fourth layer (activated with the key right of the space bar or of left shift on a 105-key keyboard) contains a lot of navigation keys and a numpad.