What is the meaning of "they finished what was left of their kiwi salad" in the following sentence?
Mr. Putter and Mrs. Teaberry took off their shoes and put their feet in the water. They filled their cups with apple tea. They chewed their tomato sandwiches. And they finished what was left of their kiwi salad.
Does it mean "When they finished eating, they left their kiwi salad"?
What does "what" in the sentence mean?