Trattoria is a restaurant where Peter and Chris go to plan their post-wedding Sunday breakfast in Vermont after Peter asks Chris to marry him in "Fresh Heir" so that he can still have access to the Pewterschmidt family fortune after Carter makes him his sole heir.
As the host goes over the arrangements, Peter verifies that there will be a table for the couple that barely got through the weekend without breaking up and the host checks to see if he can place them near the table with the couple that just hooked up and now are uncomfortable facing each other. Peter is also concerned about a vastly-underdressed cousin that thinks the world revolves around him and the host also confirms there will be a frail uncle that Peter has walk a maze of chair legs. Peter is also concerned that a newly-met single black couple he invited be prominently placed so that everyone knows they are tolerant and wonderful.
At a Trattoria in Quahog, the Griffins eat out to celebrate Stewie's first royalty check from his peanut butter commercial in "The Peanut Butter Kid".