Less You can use the Office language options to add a language or to choose the language in which the Help and ScreenTips display. The display and help languages can be set independently. For example, you could have everything match the language of your operating system, or you could use a combination of languages for your operating system, editing, display, and Help.
The question I always ask myself is why? If you really do need all of them, then by all means please feel free to install of them and have a ball. The fact is, many of us might need a few of them but hardly anyone needs all of them. So, why is this such a big deal? When you install Windows, depending on your locale, you naturally have a language pack applied to the image. For me, its en-us or US English.