"Do you talk by rule, then, while you are dancing?"

"Sometimes. One must speak a little, you know. It would look odd to be entirely silent for half an hour together; and yet for the advantage of some, conversation ought to be so arranged, as that they may have the trouble of saying as little as possible."

Is Elizabeth referring to her last day in Netherfield?

Steady to his purpose, he scarcely spoke ten words to her through the whole of Saturday, and though they were at one time left by themselves for half an hour, he adhered most conscientiously to his book, and would not even look at her. (Ch. 12)

I don't think that she was bothered at Neth. that D. did not speak to her (it only would have confirmed her that he was a disagreable man), and here, she is only speaking to him because she thought that this is more punishment to him.

Some time ago, I read in this site something about some people that were called by their first and last name, and that they were of inferior status to the gentry. It's interesting that Caroline calls Wickham three times by his first and last name in her talk.

"So, Miss Eliza, I hear you are quite delighted with George Wickham! Your sister has been talking to me about him, and asking me a thousand questions; and I find that the young man forgot to tell you, among his other communications, that he was the son of old Wickham, the late Mr. Darcy's steward. Let me recommend you, however, as a friend, not to give implicit confidence to all his assertions: for as to Mr. Darcy's using him ill, it is perfectly false; for, on the contrary, he has been always remarkably kind to him, though George Wickham has treated Mr. Darcy in a most infamous manner. I do not know the particulars, but I know very well that Mr. Darcy is not in the least to blame, that he cannot bear to hear George Wickham mentioned, and that though my brother thought he could not well avoid including him in his invitation to the officers, he was excessively glad to find that he had taken himself out of the way. His coming into the country at all is a most insolent thing, indeed, and I wonder how he could presume to do it. I pity you, Miss Eliza, for this discovery of your favourite's guilt; but really considering his descent, one could not expect much better."