posted by rfvv .
1. You know, I'm a member of the cooking club.
(What is the role of 'You know' in this sentence?)
2. You know that I'm a member of the cooking club.
(Are #2 the same as #1? What is the difference between them in meaning?)
The comma you used correctly in #1 is because of rule #2c here. The words "You know" are just introductory; they indicate that the speaker assumes that the listener already knows the facts in the main clause of the sentence.
Sentence 2 is stating what the speaker knows the listener knows; the only real difference is in pronunciation -- no pause after "know" as in #1.