。
Shall I make dinner?
Literal
Dinner [object-を] make-[polite-ましょうか].
作る ('to make') focuses on the creative act of cooking the food itself, while 用意する ('to prepare') would focus on arranging and setting up the meal. The distinction is subtle but real. ~ましょうか offers an action politely as a question to the listener — 'shall I do X?'