I too am an Alice in Wonderland fan. I agree with stocking up on mismatched tea cups and tea pots. I've seen various artistic interpretations of the tea party and paper lanterns are often depicted; if you can get your hands on plain white ones you could paint them up (checkerboard, stripes, whatever pleases you). I would also add little things like fake bugs and spiders all over the tea cups and whatnot, also we can't forget the dormouse...so if you want it darker you could switch it up and use a big fake rat. Not having seen your dining room I'm limited for ideas. Depending on space you could do that Martha Stewart thing where you take small branches, spray paint them black, anchor them in floral foam in a bucket and attach owls, crows, and other "menacing" creatures to them. Also I'd suggest hitting up antique shops and maybe specialty thrift stores for a variety of vintage hats (if it's reasonable price wise, sometimes you can find good deals). That's all I've got for now...
Cheers!