] Did you notice that Charles and Mary Musgrove, Louisa Musgrove, and even Capt. Wentworth, are all shown talking with food in their mouths? Very unattractive, but was this common behavior in JA's day?

The question about eating with your mouth full came up a little while back. The only information I could find was out of period, but here it is again:

I finally found something about talking with your mouth full, but it's out of period. It was in Maureen Waller's wonderful book: 1700 Scenes from London Life. In it she quotes from Hannah Woolley's 1675 etiquette book: The Gentlewoman's Companion as follows:

Above all, The Gentlewoman's Companion urged its readers not to "fill your mouth so full, that your cheeks shall swell like a pair of Scotch bagpipes" and to "close your lips when you eat; talk not when you have meat in your mouth; and do not smack like a pig, nor make any other noise which shall prove ungrateful to the company."

Now I would assume that English diners would have become even more fastidious in their habits in the ensuing century after Woolley's book was published, but of course I can't say for sure. I shall keep searching for something contemporary with Austen.