。
The guests thoroughly enjoyed his wife's cooking.
Literal
Guests [topic-は] he [possessive-の] wife [possessive-の] cooking [object-を] fully savored.
来客 ('visitor / guest,' literally 'come-guest') is a formal compound. 達 is the plural-marking suffix (like ~たち). 賞味する ('to savor / enjoy the taste of') is more formal than 味わう — common in formal descriptions of food appreciation. 奥さん ('wife') is the polite form for someone else's wife; 妻/家内 refers to one's own wife.