Thanks for all your input and interest. Since I first posted these pictures, I have had the table examined in person by three antique dealers/appraisers, Winston Garth of Garth's Auction and Antiques (here in Pensacola), John Dwight Stevens, of Stevens Auctions in Aberdeen, MS, and Ann Benton, of Americana Advisors, who worked in New York with Federal furniture for a number of years. I also have sent these photos to two Federal furniture dealers in NY and Conn. All five have indicated that they believe it is a period Federal New York table. Mr. Stevens estimated around 1800, Mr Garth, "early 1800s."
As far as pinning it down to Phyfe's workshop, the substrate of the table is made of joined mahogany boards, rather than white pine, which Jesse Goldberg of Artemis Galleries has stated was one of the indicia of Phyfe. They have separated over time in two places and created the veneer cracks that Jacon4 was referencing. I think that the most telling feature is the carved cabriole legs, which are quite out of the norm for that time period. However, there is a very small number of known tables with these legs. Two are the card tables from the Garvan collection at Yale, one is a dressing table known to have been made for Phyfe's grandniece, and the fourth is a work table sold by Christies in 1998. The lot notes for that sale state:
"The design of this work table successfully combines sinuous curves and geometric casework to create one of the most sophisticated and elegant forms from New York's Classical era. Attenuated cabriole legs on classical furniture are rare and only found on a small group of card tables, work tables and a dressing table. This work table most closely resembles a pair of card tables in the collection of Yale University Art Gallery illustrated here with waterleaf-carved legs, paw feet and almost identical carved rosettes on the canted corners above the legs. A dressing table that descended in the family of Emily Phyfe Dunham, Duncan Phyfe's grandniece, bears legs similar to those on the Yale card tables and the work table offered here and provides the basis for the attribution to Phyfe's shop (Nancy McClelland, Duncan Phyfe and the English Regency (New York, 1939), pl. 152). The remaining examples in this group all feature reeded legs and lack waterleaf carving (a card table sold in these Rooms, The Collection of Ronald Kane, 22 January 1994, lot 376; a work table sold at Sotheby's New York, 28-30 January 1988, lot 1810; a work table sold at Sotheby's New York, 23-24 June 1993, lot 455)."
I was going to attach a photo of the underside of the table showing the joined mahogany substrate (as well as showing braces which have been attached to the underside to stabilize the veneer cracks.) However, I can can't seem to figure out how to attach a photo in the reply mode.
Sorry for the length of the post, but I am cautiously optimistic that this amazing table can be attributed to Phyfe or his workshop, and so far it appears to be one of a kind. Any further insights or information that you have would be a great help.