Knoll tulip table - real or fake  

The base
looks like Burke.

Thanks for the response. ...
Thanks for the response. From what I've read the Burke mounting plates are square, but maybe that's just for the chairs. Are Burke mounting plates round?

looks real to me...
It looks real to me. From what I understand the Burkes don't have a mounting plate at all and the base screws directly into the table top.

Thanks mvalen,
I just don't...
Thanks mvalen,
I just don't quite get the screws. Everything I have read about the originals say that no screws are visible and the top screws on to base via a metal rod.

I could be wrong but I think...
I could be wrong but I think that is only true for the side tables... The larger dining tables have screws.

It's real
The wood plate that is the transition between the table top and the base (it has the threaded insert that attaches to the long threaded rod at the top of the base) is attached with screws.
If you unscrew the top it often also will have dowels to guide it when re-attaching the top.

I thought it might be, too.
But I also see what I think Riki sees: parallel sides on the stem. This was always the kiss of death for "tulip" tables for me, but it seems like the Knoll versions have become less refined somehow over the years. Maybe it's the poor quality photos or just me.

I see only
a short section of the shaft that might be cylindrical -- maybe four inches ?
Here's a table that has a much longer cylindrical portion of the the base -- and the wrong beveled edge ? -- presented on a blog as Saarinen:
http://midcenturymodernist.com/2008/furniture-objects/dining-room/saarin...

Ours has the same support...
Ours has the same support beneath the table top and newer Knoll sticker.

SDR
The table is that blog post is a Burke. You can tell by the soft rounded edge to the top (Knoll has a deep bevel) and the shape of the base at the top. It's wider and more flared than the Knoll.

I was once ...
...in Istanbul and visited the bazaar. What a great experience that was. There were a lot of trinkets there to buy, among them many made out of alabaster or onyx. Most of them had a sticker on them that said either alabaster or onyx. Onyx was always more expensive than alabaster.
I became very interested in a serving dish that was either alabaster or onyx but had no sticker. I asked the seller, "Is this alabaster or onyx" He said, "it's onyx of course." I responded, "If it's onyx why isn't there a sticker on it that says it's onyx.? He responded without blinking an eye, "You want a sticker, I'll put one on."