Represent a Class which holds translation Strings
You haven't given much context about how you intend to use this class, which is always important.  In my experience (echoed in comments), there's not much use case for needing all translations of a string at one time.  The use case is more typically that you need to render the UI in a particular language, so you need a bunch of German strings but none of the other languages.  Also, you want to be able to easily add support for additional languages, ideally without any code changes.  That's what resource bundles are for, it seems like you are trying to reinvent the wheel here.  If you think that resource bundles don't solve your problem, you should give more context.