Pluto's is located on University Avenue in Palo Alto. It's often filled with hungry Stanford University students at all times of the day.
Pluto's serves cafeteria style food. You pick up a tray, order your choice of items a-la-carte (there is a daily special/combo that you can get)--get a salad, sandwich, or whatever you want, and then pay at the cashier.
A carved turkey sandwich costs, for example, $7 and a ceaser salad with chicken, as a main entree, costs around $10. The prices are resonable and rather cheap for the portions you get, and it's definately not "fast food" like you get at Burger King.
in all, it's a good deal. The cafeteria style, while kind of strange for a University Ave Restrauant at first, but you get used to it. It's a good eat for a good bargain.