This is absolutely a container for a spare/replacement typewriter ribbon.

As for what that text around the rim means, though, that’s still a mystery. Maybe it’s just decorative, a random assortment displaying the kinds of letters and numbers one might be typing with this ribbon? Kind of for advertisement purposes… Looking at the font of the letters, they look pretty clean and uniform (for a typewriter), so maybe it was meant to suggest that this was a high-quality ribbon that would help you type cleaner-looking letters?

(Still, if that’s the case, then their marketing department kind of missed an opportunity there, to instead spell out something that would hopefully make it more appealing than purely random numbers and letters.)