84" x 42" is plenty brother... damn it, that was the table we built for the munchkins in the WIzzard of Oz back in the day! Lol
Kidding! I mention this because Brie and I bought a table off craigslist that was 10 position so I assumed 94" - 96" given there were 10 positions
We drove like 2 hours to go and get it, it was in new condition and I thought it was a great deal at $350, well we didn't ask dimensions ahead of time and the lady also drove 2 hours to show it to us from her father's estate. It was only 84" I'm standing there going "how the hell are you ever going to fit 10 grown people around that??" Lol
It was in new condition and obviously expensive when it was bought from some poker store so we bought it, yet to get it in play but I figure for 8 players it would be plenty and more space than our 96" in the dining room.
Which can easily fit 10 but I think it would be snug with eleven given that the dealer needs extra space on his side.
So let's break it down to math, a standard 10 player table is 42" x 96" that means a 42" half circle at either end leaves 54" between the radius. Double that is 108" of rail length. The circumference of a 42" circle is 132" (yes half on either end but still adds up to a full circle) so we have 132" and 108" for the straight rails giving us a total of 240" or roughly 24" per player. That may sound a bit tight but that is what you have on an average table and is actually pretty comfortable.
So we increase the table dimension to a true 48" x 96" our straight rails drop to 48" or 96" for both, the cir. on this one is 150" so 246" total rail lenght. In reality if my math is correct we are only increasing the total lenght by 6"" but we are adding an 11th person so now we are down to 22.36" per player so you are loosing about 1.5" of table space per player. Doable yes but an average 6 ft human sitting with his elbows resting on the rail comfortably is about 24"... measure your office chair, should be about 23" and your arms hang over the rails on either side, so less than 24" per player is going to be a bit cramped, just my opinion based off the math, I have played 10 plus a dealer on a 96" x 42" and with a full table it is snug.
In comparison the first table I show givin that math works out to 216" of rail or 21.6" per player and I can tell you I would not want to play 10 on that table!
Hope that helps and makes some kind of sense to answer your question.
Fellow chipper Ben