I believe that this has a double meaning.
"You have" can also mean "Εσύ έχεις".
Yes, what you see here έχετε is the plural. But it's used not only for plural but for polite speech. Εσύ έχεις just έχεις witho εσύ is singular and fine for all other occasions.
Is there any way to know from "you have" that what is being asked for is the plural Greek translation rather than singular?