Train is quicker and less expensive but requires a transfer. Bus is direct. Both appear to cease to run prior to midnight, though. No Delta will not transfer your luggage. A 19 hour layover arriving prior to midnight is not practical for a day trip to Tokyo, in my opinion. As with all international flights, arrive 2.5 hours prior to departure and so arrive at 3:45 PM.
I would be inclined to catch the train from HND to NRT, sleep at one of the convenient airport hotels in Narita via the free hotel shuttle, tour Narita via cheap circle bus, and head back to NRT via free hotel shuttle for a late lunch at any one of the dining options at the airport. Narita the town and Narita the airport are both quite nice. The time and cost associated with a trip to Tokyo are better suited to a multi day visit.
Two night layover in Narita some months ago and concluded travel to Tokyo was 2 hours each way, $40 round trip, and 3X the price for a hotel in Narita; and to my delight Narita proved to be a wonderful location for a two day visit with the free hotel shuttles, cheap circle bus, tourist friendly malls and temples, and endless options for dining in town or at the airport. The Crowne Plaza ANA Narita proved to be a good value and a good view of the planes departing.