particle と - Grammar usage of "と、～た"

I'm not completely sure on the grammar usage of と、～た, in these following sentences, but have been given the general explanation that the imply an unexpected result following a normal (one time?) action.

１．弟は昼ごはんを食べると、片付けもせずに出かけてしまった。

２．私が「ごめん」と言うと、友達は「あやまるのはぼくのほうだ」と言った。

I'm also unsure of how to translate と as it applies to the first half of the sentence in these cases either, or the tense.