I know it breaks the "one table <=> one chair" detail, but my current fortress has the following layout.
# # # #
## ############# ##
X #^v X
## ##D#D#D#D#D## ##
# # c c c # #
# # Dctc ctc ctcD #
# ^ # c c c c c # #
# v D ctc ctc D #
# # c c c c c # #
# Dctc cTc ctcD #
# # c c c c c # #
# D ctc ctc D v #
# # c c c c c # ^ #
# Dctc ctc ctcD # #
# # c c c # #
## ##D#D#D#D#D## ##
X v^# X
## ############# ##
# # # #
c = chair (rock thrones), t = tables (rock), T = Very High Quality (rock) table from which I designate the whole room, D = doors and # = Walls
(Also shown are corridors and representative other "blocks" without their room details. The "#^v" bits are walls, upramps, downramps that progress in such a regular fashion throughout my structure to provide alternate routes to the "X" stairwells.)
I also used two different stones. Marble for artefact table (and its set of chairs) and the eight complete corner/edge table-sets, something grey (could be claystone) for the four "inbetweeny" table/chair sets. Carved out of Dolomite (being in the area between surface and first cavern where that prodominates) although I used the absolute best claystone doors to fill the gaps, for consistency of appearance (using the marble doors, from the quarries between Caverns 1 and 2, for somewhere else at the time).
It appeals to my aesthetic sense, although it's not
the best dining room I could have created.
I have a similarly-sized room dug out of the marble layers (where my bedrooms are) which I've only so far put the planned (no-quality, left over from the initial masonic training) marble doors into the similar edge-gaps, and haven't yet gotten around to working out (and commissioning, from the only best masons and only within the marble workshops ) the number and variety of furniture I'll be placing in there, in this new room intended mostly to be useful for those dwarfs who need a snack just before or after sleeping, plus a closer cafeteria to the magma workshops (below 3rd cavern, above magma sea, which may eventually get a fine dining experience of their own in a gold-plated room).
(So far, I've got nothing more than "pre-planned corridors" in the gap between Cavern 2 and Cavern 3, but if I decide to do anything with it I'll be putting a dining room there as well... I've got loads of lead to spare, so maybe I'll line the place with that.
)
Personal dining rooms, offices, bedrooms and tombs (appropriate to for those that require them, the mayor and the count, to name just the two who I can remember doing so, off the top of my head) are generally 5x5 rooms with doors and all necessary furniture being made from the metal desired by the owner. (Necessary, as in: defining furniture (and table/chair where that was chair/table) set half way along one side of the room plus other required location non-specific furniture placed logically (cupboards generally only in bedrooms, chests in any, weapon rack and armour stand at ready in both dining room and office) in the corners of said rooms. I've only just been made into a County, so I haven't placed all the Count's furniture yet, and may have to buff various rooms up with some masterful statues in copper (his favourite metal).) All of which is utterly boring, but fits within my layout system (which gives ordinary dwarves 3x5 rooms laid out in 3x2 arrays within the same intra-corridor squares as I use throughout the whole complex).