Kramer`s fixation on Coffee Tables

I just saw the episode "The Truth" a couple of days ago. It`s about George telling the truth to his girlfriend about her and her going to a mental instituition while she has Jerry`s tax papers for his audit. Anyways, Kramer is dating Elaine`s roomate and he has a piece of glass which he says that he will make with it a coffee table for Elaine and her roomate. Now, this episode aired about 2.5 years before the episode "The Cigar-Store Indian", in which Kramer goes to Elaine`s boss about the idea for a coffee table book on coffee tables. Ironic, or was it all in the planning for the Seinfeld creaters? And is there any other references to coffee tables before the Cigar-Store Indian episode, or no?