If you are you asking whether you need to provide a translation for information in a stamp which is not in English or French, obviously the instruction is yes.
If you are asking whether dates or number in English need to be translated, they are already in English.
If you are asking whether a translation is needed for information which is not in English or French but it is the same as information in the stamp which is in English, how does the interviewer confirm they are the same without a translation?
If you are asking whether it is possible the interviewer will allow the latter sort of stamps to pass without a translation, based on a reasonable inference the information is the same, DESPITE THE CLEAR INSTRUCTION TO PROVIDE A TRANSLATION, there have been many reports indicating that indeed, IRCC appears to be flexible and not demand a translation, at least SOME OF THE TIME, BUT other reports amply show some times the applicant will be instructed to provide the translation, which of course results in some delay.
My impression is that how IRCC processing agents approach enforcement of the obligation to provide a properly authenticated translation varies depending, at least in part, on how legible and easily understood the stamps are without a translation, and perhaps depending on how many stamps are involved, and perhaps depending on other circumstances (such as how comfortable the processing agent is in concluding the applicant has fully and accurately disclosed travel history and other information).
Finally, if you are asking whether partially translating stamps might be allowed or otherwise might suffice (such as the interviewer not noticing not all information not in an official language is translated), PERHAPS. Here too, however, if so, that will also be DESPITE the obligation to provide the translation. Thus, here too how it goes will likely vary and depend on various factors. Like the number of stamps involved.
Leading to this . . . from the number of stamps you report having in your passport, prudence suggests complying with the instructions. May be expensive but should NOT be a fortune. May necessitate a concerted effort to find reasonably priced translation services.
Worst-case scenario, if you do not provide the translations, is you will be asked to provide the translations, resulting in some delay. Might be worth the gamble.
Note: if you are considering providing translations for some stamps but not all containing information which is not in one of the official languages, probably be a good idea to make it clear that it is not a complete translation. No matter how good the odds are this will work, they are not good enough to risk being perceived to mislead by omission.
My guess is that stamps containing a rather small amount of information in one of the European Latin languages are quite often not a problem, especially if very few in number. Indeed, while it was years ago, I too did not bother to provide a translation for a few otherwise easily read stamps with some information in Spanish and Portuguese, without a problem. I doubt such examples indicate much about how it will go for someone with numerous stamps in various languages, and especially those involving a significantly different alphabet.
