I saw all the same characters that kkmcan just mentioned seeing when I was there in early October, but they are not limited to just those. It seems to be a rotation, like certain characters are there during one period and others come in at different times of year, but you never know exactly who you will get. Sometimes the Mad Hatter will stroll in. Sometimes Gadget will come in. Sometimes you get Aladdin and Jasmine or Rafiki and Timon. We have seen Meeko there. The Beast and Jafar used to visit years ago.
When you arrive, they now have this thing where they shuffle you off to a photo opportunity with Pluto and make you take a picture! It used to be that you had the choice of whether or not to get in the photo, but now they make you! And of course, they print the picture and put it in a Goofy's paper frame and ask you to pay over $32 for it, and I THINK that they will load it onto a PhotoPass card once you buy it if you want them to. That is what I heard. However, I have heard of many folks just kindly asking the photgrapher to take a picture of them with Pluto with their own cameras. Of course, they will do it but they want you to buy their overpriced picture so they are not happy! I mean, the pictures do come out cute and all - they bring them to your table and tempt you with them - but $32 is not worth it to me just to get the Goofy's paper frame!
As far as photos at the table with other characters, I think they do have a PhotoPass option but you have to pay them right then and there. So unless you have money to spare, it makes more sense to just use your own camera when the characters drop by!