the first one is "he drinks coffee before work," and the second means "she reads after lunch." "~no ato ni 〜の 後「あと」 に" is used to mean "after," and "~no mae ni 〜の 前「まえ」 に" is used to mean "before." if a verb goes before these words, you don't need to use "~no の," and in the case that either adverb follows a past-tense verb, it is not necessary to use ~ni 〜に at the end.