There is a good thread over at Highrankings discussing the impacts of tables on SEO. The member Karri asks about how the various tables on her site will affect how a spider interacts with the site. She is concerned that the spider might not be able to find the relevant information in the right order. Good question.
Several of the resident experts say that search engines don't have a big problem with tables and that "problems always turned out to be non-standard code, not the use of tables per se". You can also nest tables to your heart content and spiders will be able to get to the code. This is perhaps another SEO urban myth as back in the beginnings of SEO, some search engines had problems with tables in that nesting many levels deep often caused a spider to leave or not get the complete information.
Scottie follows up with some overview that there are a couple schools of thought. One that having content higher up on the page will be better than having it at the bottom. The second thought is that it doesn't matter where you content is located at its all the same to the spider according to Jill Whalen.
Things get a bit interesting when Dan Thies jumps in and disagrees with Jill and Scottie on the advice that content doesn't matter where it appears on the page its all the same. Looks like an SEO showdown in the making. Dan says it does matter and gives some examples. One how search term is at the beginning and search terms at the end of the content. See Dan's tests here and here. Those links to the tests might speed along the spidering process for the test (hopefully). Watch this link for results on which pages shows up first.