Yeah, the Bamboo i have is around the size of an A4, perhaps a bit smaller. Note, however, that the drawing area is smaller than the tablet itself. It's generally listed as being 14,7 x 9,2 cm, but you can see it on the image here:



The encircled markings are the corners of the area, the pen is as big as a normal pen. The area is a bit on the small side, but is still entirely possible to work with, and is MUCH easier than a mouse once you get used to it. Honestly, if it's the only tablet you have (i have two in use, the Bamboo and an Aiptek thing, the latter having maybe twice as large dimensions for the drawing area, which makes transitions between the two a bit funky), then i don't think the size will be that much of a problem.

tl;dr the Bamboo is not the BEST tablet but it's absolutely fine for the purpose if you can't find anything better