First: The correct way to spell the third person singular of the indicative of "to be" (terza persona singolare dell'indicativo di "essere") is è and not é; if your book is reporting otherwise, it's wrong.
That said, in Italian there are three different ways of translating the (singular) personal pronoun "you", each more formal than the other:
"tu": this is the most informal form, it's used with friends, family, between young people and sometimes long standing acquaintances. "Tu" uses the second person singular of verbs: "tu sei, tu hai, tu vai".
"Lei" (notice capital letter): this is the most common formal form, it's used between colleagues, students and professor or any other normal formal context. "Lei" uses the third person singular of verbs: "Lei ha, Lei è, Lei va".
"Voi": this is an old and almost unused form, it's used when you are speaking to extremely important people, like the President of the Republic or the Pope. It's still used in some parts of southern Italy in place of "Lei". "Voi" uses the second person plural of verbs: "Voi siete, Voi avete, Voi andate".
About this: "Lei é l'allievo" sounds like "You is the pupil," when I was expecting "Lei sono l'allievo," such as "You are the pupil." It seems like a weird translation.:
"You is the pupil" would be wrong in English, there is no other way of saying this than "You are the pupil".
"Sono" is the first person singular or the third person plural of the indicative of "to be", the only places where you'll find it is in sentences like "io sono l'allievo", "essi (or loro) sono gli allievi".