Start outside and work your way in
餐具的擺放是根據上菜的先后順序以用餐者為中心、從外到內擺放的

Kate will already be well aware of this golden rule for negotiating the cutlery.
凱特王妃想必已經對這個餐具擺放的金科玉律了如指掌。

Napkins must go on a guest's lap and be placed on the chair if the guest has to leave the table during the meal.
餐巾必須放在客人的腿上，如果客人在用餐期間離開飯桌，則可以將餐巾放置在椅子上。

They only go on the table at the end of the meal.
吃完飯以后，餐巾才會出現在桌子上。