Who coined the term ‘yada yada yada’, and what does it mean?

Jerry Seinfeld's gang coined the term "yada, yada, yada," enthnicizing "blah, blah." In large cities, the hip crowd uses statements such as "words, words, words" to convey an assumed, deeper meaning in the conversation.

http://marygardner.com/the-language-of-the-future/

One resource says that "it seems certain that yadda-yadda-yadda is a variation of a phrase used in pre-1940 vaudeville".

Neither Seinfeld nor his writers invented the term. It can be traced back with certainty to the controversial comedian Lenny Bruce in the early 1960s. Bruce grew up in the 1940s world of Jewish club comics, who often used routines and expressions dating back to the vaudeville era. But since the term was transmitted orally, it's hard to find early printed examples.

Incidentally, the similar expression yackety-yack, which was popularized in the 1950s, can probably be related back to the term yack, used before 1900 to mean talk. Blah-blah-blah shows up in the 1910s.

The updated and very spiffy Random House Webster's College Dictionary offers some surprises to students of the English language. Among the new entries, for example, browsers will find yada-yada-yada, defined on page 1489 as "blah-blah-blah."

http://query.nytimes.com/gst/fullpage.html?res=9802E0DC1238F931A1575BC0A96F958260&sec=&spon=
http://findarticles.com/p/articles/mi_m1571/is_n39_v13/ai_19964938

The word "yada" is also Hebrew term for sexual activity, and has been used on the Seinfeld show in that context.
http://www.moseshand.com/questions/p17ax.htm

Merriam-Webster considers the source of "yada yada" as empty talk to be the British dialect phrase, "yatter-yatter."
http://www.merriam-webster.com/dictionary/yada+yada

Ha the Jerry Seinfeld episode. Where George's girlfriend uses yada yada yada instead of words. Sometimes what she was going to say was important but she said yada yada yada instead.

https://en.wikipedia.org/wiki/The_Yada_Yada

There is certainly no connection between the phrase and the Biblical Hebrew term for sexual activity. It seems that the phrase is some sort of light comedic Yiddish version of änd-so-on-and-so-forth", or "etc. etc." (Hebrew: "V'chuleh, v'chuleh...").

An intersting thing is that this actually sounds Norwegian.
Norwegians (at least in eastern Norway) say "Jada, jada, jada" in about the same meaning.
And this has nothing to do with Seinfeld or US television -
"Jada", or more correct "ja da", translates something like "of course".