PWMTrav
Thank you very much for the link.
I appreciate eating places that are open all through the day as I prefer to eat when I'm hungry; I tend to eat early lunch, so I am hungry again early in the evening.

I understand this bit of whimsy is a highlight at Mercato Centrale!

Going to most places in Italy with a schedule or agenda is an exercise in futility! It's one of the best places in the world to reduce the pace, wander around and just be curious.

If you haven't heard of this already, make sure you take the time to notice the door knockers while wandering the streets of Florence.

Il Vegetariano is an amazing place. Rustic Cafeteria-Osteria with vegetarian and vegan food, many organic ingredients. Incredible atmosphere, no reservations - be there at least half an hour before it opens or try your luck rather late.

This is how it works: the first person in should immediately get in line at the cashier at the back to order food and drinks. The second person in takes care of getting a nice table. Next, take a look at the hand-written menu on the wall and tell the person in line what to order. After placing your orders and paying (cash only!), take the receipt to the food counter and get your food and drinks. Enjoy!

http://www.il-vegetariano.it/

I really liked La Bussola, http://www.labussolafirenze.it/, ended up going there a couple times on my last trip for lunch.

Good to know. I can't tell you how many times I've walked right by that place. I like to walk Florence when the streets empty out at night, and one of my favorite paths is to walk south on via Tornabuoni and turn left onto via Porta Rossa right at Santa Trinita. There's a lot of history on those roads.

Reporting back on the food court in Mercato Centrale : Went there for a burger for lunch - very good.
Went back later in the afternoon for snacking and drinking - very enjoyable.
I think I'm going to forget about concepts such as lunch, aperitiv , and dinner and just swing by the Mercato when I feel peckish.
In short - the food court is fantastic, something for everyone.

What stalls have you tried besides the burgers? One thing to do is to swing by before 2pm on the ground floor and try a lampredotto sandwich from Da Nerbone. Then, if you like it, try one from the stall upstairs later on in the evening. They're both very good, but Da Nerbone is the classic.

Florence isn't known for its seafood (heh), but Livorno is, and it's well represented at the seafood stall. Great fritto misto, or baccalà if you go on a Friday.

I'm not sure if I mentioned it, or pasted my blog link, but another place to get a snack and a drink any time of the day before 9pm is Fiaschetteria Nuvoli. It's located a block off of tourist central, but manages to be very good. Upstairs has some counter seating, but they have tables downstairs.

I had a nice mix of snacks :some small sandwiches with anchoves and truffel, icecream, slices of roastbeef, open sandwich with mozarella and tomatoes and a few glasses of prosecco.
I don't like the look of the lampredotti so I am not sure that I'll try it.
The Fiaschetteria Nuvoli is on my list so you must have mentioned it.

Lampredotto tastes a lot better than it looks, honestly. It's a classic Florentine dish, hold your nose and go!

I can now also recommend Trattoria Rocco in the Mercato di Sant'Ambrogio.
Primi 4.5 €, Secondi 5.5 €, Contorni 3,5 €. Dessert 3 €,
Wine 2 €.
Open Monday-Saturday until 14.30.
It seems that they are open very early for lunch as they are also selling their food as take away.
Add : Better to eat early than late. Saw lots of people waiting in line at about 13.30 today.

There are students that live off of that place. I had entirely forgotten about it, but it's also a solid place to try lampredotto if you're on that side of town.

Their Bresaola is very good quality. So is their roastbeef.
The wine (white) is, in my opinion, perfectly decent.

If you like quick stuff like that, check out Passaguai. It's on the other side of the river on Borgo San Frediano. Cool neighborhood, a little slower, and comparatively fewer tourists, than the other side of the river closer to the Duomo. Also nearby is Il Santo Bevitore. If you're on that side of town and want to walk a little more Enoteca Le Barrique is close. La Casalinga is a little further (but east, so a good detour before you turn north to cross the river again) - that is one of my favorite restaurants in Florence (but order things written in CAPS on the menu, those are specials).

Here's a map link:

https://goo.gl/maps/hLf3S9T1Rs92

Thank you for your further suggestions.
I'll note them down for my (hopefully) next visit to Firenze.
This is my last evening here and the weather is not nice at all so not in the mood for too much walking.
I'll probably just go to the Mercato Centrale (I have more or less lived there these last few days - nice place to shelter from the rain).
About the drinks in the Mercato Centrale: in addition to ordering water, soft drinks, and beer at the table, you can also order wine, prosecco, and champagne. The wine would be the 'house wine' I expect - anything else, you'll have to pick up yourself.