Originally Posted by LapLap

Here is how I would tweak your messy day 3 itinerary:

day 3, freestyle start at Ueno and wander across to Nezu temple. Close to Nezu temple is Yoshibōrin, a highly regarded soba restaurant. As Yoshibōrin is popular, either get there by 11:30am (you can see Nezu Temple afterwards) or be prepared to queue. https://tabelog.com/en/tokyo/A1311/A131106/13018408/
From Nezu Temple, get the 茶51 Bus to Akihabara (if you can’t use Google maps to find the bus stop there is one right next to Exit 1 at Todaimae station) it’s a 15 minute bus ride.
Akihabara station to Higashi Ginza station is a 15 minute journey on the Hibiya line
Personally, I think you should leave out Ginza/Yurakucho and go straight to Shibuya for the 6:30pm food tour from Akihabara (30 minutes on the Yamanote line). Instead see Ginza/Yurakucho on day 5.

It is REALLY easy to figure out travel times now. You find your starting point in Google maps, press the “destination” button, put in your destination (check the date and time to ensure you aren’t looking at an unsuitable 3am suggestion) and it will give you journey times. Always add at least 20 minutes.