That's the numpad. Typically the numbers will have the same color as the Fn key so it'll be quite easy to recognize how to type it. In this case it was a bit strange
On some laptop computers, the Num Lock key is used to convert part of the main keyboard to act as a (slightly skewed) numeric keypad rather than letters
https://en.wikipedia.org/wiki/Num_lock
To type those numbers in normal mode (i.e Numlock OFF) you'll need to hold Fn. If you don't want to keep holding it you can toggle NumLock (Fn+NumLk in your case) and now the function of those keys will be reversed: to type the normal characters on those numpad keys you need to hold Fn