Paul McCobb? If not, please assist with designer or maker.  

This looks like common low...
This looks like common low brow 50s type furniture. Mccobb items are solid maple generally (planner group), and don't have brass caps on the legs. This is the kind of 50s furniture, the common people bought in the 50s-60s. The people that weren't well off had low brow versions to choose from, which were copies of Knoll, Herman Miller etc..
I have a theory that most high end design stuff is void of brass leg caps. There are exceptions, but not many.
I still like this type of furniture, its good starter stuff for young hipsters.

Hipsters loveEEEEEEEEE to...
Hipsters loveEEEEEEEEE to put birds on this furniture.
as for the brass caps I have found the same, sometimes I will see some nice lines from across the thrift store then I get closer just to be disappointed when I see the brass caps.
General rule of thumb is brass = cheap furniture probably sold at Sears or Montgomery Wards to the working class who wanted high design but could not afford the designer prices.

Wow, a very helpful tip...
Wow, a very helpful tip about the brass caps. I JUST emailed someone about a set of chairs that I thought were great mid-century -- but yes, they have brass caps.

Does anyone know what purpose...
Does anyone know what purpose the brass caps served? Were they just the easiest way to add those adjustable feet? And if so, why were adjustable feet so important? Good Danish furniture doesn't seem to need them.

Don't discount brass caps...
Don't discount brass caps entirely as lot of Dunbar + Probber pieces have brass caps. Its the quality of the brass and the capping that's important -- when you see them in person the quality and thickness of the brass on designer pieces is far above the OP's table. They're also usually on square legs, not round. As a probably more basic rule -- if it has wood-grain formica, walk away.

But even the occasional...
But even the occasional Knoll credenza or table will have wood grain formica! Doesn't forgive it though ... I'm not a fan of faux finishes.

A lot of the DUX stuff from t...
A lot of the DUX stuff from the 50's also feature brass capped legs.