Why can't each state be responsible for the tax tables?
In my experience most states do provide these. On paper or PDF.
Well, that's an exaggeration but really some provide txt, others csv ( and really, I can swear our accountants only get the data in a paper book from one state, can't remember who though, maybe it's changed over the years). But anyway, even the electronic copies generally have different schema and, in some cases, are difficult at best to interpret. My small company deals with 8 states if I remember correctly because of our remote sales force. We have a staff account who spends about half her time on this in a month and that's with support from IT. Adding 42 more states would be horrible.
So the fix of having the states provide data would be somewhat more manageable if they could come up with a standard format but in my mind I think the states would be better served by coming up with a common internet tax at a flat rate instead of imposing sales tax on out of state orders. I realize sales taxes are used by different states to paint themselves one way or another so I'm not suggesting every state implement the sames sales tax rate, just that if their residents are receiving goods from another state that they pay a flat rate tax for that. Anything bought locally would still be subjected to the usual sales tax.
Of course I can hear the low sales tax states screaming already about the Feds imposing on them and I can hear the higher sales tax states moaning about how everything their residents buy is now through the inter-tubes because the flat rate is lower than their sales tax... So, you know what, forget I said anything! This is why I am not a politician.