The word “Eclat”, in context to the sentence, means “brilliant display or elegant display”.
Step-by-step explanation:
In the mentioned paragraph, it is described that a respective woman is a person who likes things to be done almost perfectly. Due to this, she tries to speed up her otherwise sluggish aid Millie. However, she takes the plates and other things needed to be setting the table in the parlor by herself and puts them across with “utmost elegant/brilliant display”.