The guys that sell them to you sell furniture. It's almost exactly like Oblivion
This is a great thread, because I just became irritated with this last night after having to run to Dragonreach or to that dungeon with The Caller over and over for the same reason.
I have my house, and the alchemy table (which I could care less about) and got them from the dude in Dragonsreach who sells the furniture. Problem is, I went looking for that dude last night thinking I had missed the enchanting table package and when I found him, there were no options to buy additional packages. I had indeed bought everything you could get for the house the first time. At least, for that particular house.
Maybe you can get a table with that mansion that's for sale in the other city, but you can't in Whiterun. Either that, or there's a bug of some sort.
While we're on the subject of enchanting tables, can I mention how enraging it was to find out that once you disenchant an item and learn a particular effect type, you can never replace that effect type with a more powerful version? Yes that's right. Early on I broke down something and enchanted a war axe with a +10 Frost Damage enchantment. Yesterday I tried to learn a +20 version and was told I already knew that enchantment. So basically I could be walking around at level 80 with 100's across every magical category and I will never be able to stick frost damage into anything at a higher value than +10 damage. How wack is that?
Why can't we forget enchantments? Better yet. Why can't we get better at them and replace them as we relearn them at higher levels?