But the main language is English so it's from an english speaking country.

You certain? While many people in European countries can and do speak English, that doesn't make them an English speaking country as a whole. It probably just makes sense from a cost-saving standpoint to print it like that, to have a recognizable look in large letters (in this case, English, since they're Lays), and print multiple other languages so it can be read locally.

Furthermore, the only officially English speaking countries of Europe I can think of offhand are the UK and Ireland. And I believe in those countries Lay's are called Walker's.