Yes, ESQUIRES is a Scrabble word!

Letter values in Scrabble US: E 1, S 1, Q 10, U 1, I 1, R 1, E 1, S 1.

Is it a valid word?

ESQUIRES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(Middle Ages) an attendant and shield bearer to a knight; a candidate for knighthood
a title of respect for a member of the English gentry ranking just below a knight; placed after the name

Not playable in Scrabble US: ESQ.