Exegesis:

panti de hō edothē polu, polu zētēthēsetai par’ autou ‘from everyone who has been given much, much will be required.’ panti is in the dative under the influence of the case of the relative pronoun hō that goes with it (inverse attraction). par’ autou takes up panti. The repetition of polu is intentional. The implied agent is God.

hō parethento polu, perissoteron aitēsousin auton ‘from him to whom much has been entrusted, even more will be demanded.’ parethento and aitēsousin, though both in 3rd person plural, are best understood as impersonal plurals equivalent to passives. paratithemai means here ‘to entrust,’ ‘to commend,’ ‘to deposit.’ polu and perissoteron lit. ‘much’ and ‘more,’ are best understood in their literal sense. For the meaning of the verse, see commentaries.

Translation:

An ‘if-’ or ‘when-’ clause may be preferable again, cf. 9.24.

Of him will much be required, i.e. he will be asked/expected to give much, ‘God will expect him to give much.’

Demanded of is closely synonymous here with ‘required of.’

More, i.e. than has been committed or deposited.

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.