The king spoke

This refers to Nebuchadnezzar.

Ashpenaz

This is the highest social class.

These two negative words together emphasize a positive idea. AT: "with perfect appearance" (See: rc://en/ta/man/translate/figs-litotes)

This is an idiom. This means they knew much and could organize and use that information. (See: rc://en/ta/man/translate/figs-idiom)

This is the large house or building where the king lives.

"Ashpenaz was to teach them"

The king's officials did this task for him. AT: "The king's officials counted out for them" (See: rc://en/ta/man/translate/figs-metonymy)

the special, rare, good foods that the king ate

This can be stated in active form. AT: "Ashpenaz was to train these young men" (See: rc://en/ta/man/translate/figs-activepassive)

"taught skills"