Someone dominates a conversation by not letting others get a word in. I'm thinking its a combination of snow job and fillibuster (though not political in nature).
EDIT: to clarify, Not quite a long tedious speech; Speaker prompts a response but doesnt actually allow the response to be heard because the speaker begins talking again as if the response was heard.
Best Answer
I would say "He monopolised the conversation"
or "Insisted on taking centre stage the whole time"
I have also heard family members say "He was holding court" - which I think is a commonly used sarcastic reference to the way a Judge commands the attention of everyone in court .