"I move to strike the last word" is a phrase that is being used in the Judiciary Committee hearings. In simple terms it means that the speaker is asking to take an immediate turn to speak for five minutes.
It is used so the members have additional time to debate an amendment. There is a five minute rule which allows members to speak for 10 minutes - 5 for and 5 against the amandement, if allowed, this can secure additional 5 mnutes of time to continue the debate. It is often used to prolongue the debate indefinitely.