Exegesis:

kai eipan autō ‘and they said to him.’ Subject of eipan are the attendants, or the audience of Jesus, preferable the former.

kurie, echei deka mnas ‘master, he (already) has ten minas.’ echei is emphatic. For the textual problems cf. GOOD NEWS BIBLE and commentaries.

Translation:

He has ten pounds expresses the speakers’ astonishment at the king’s unexpected, and in their eyes unfair decision, cf. “he has ten pounds” (The Four Gospels – a New Translation), “he has ten already” (New English Bible, similarly in many other versions).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.