You should take a look at Sigil (see the Sigil forum on MobileRead). You would write your manuscript in Open Office as you are today, then save it as an html file.
Bring that file into Sigil. If you know html getting the tables correct won't be too difficult.
You now have an EPUB formatted ebook. Run this through Kindle Previewer and you have the Kindle version. This way you can publish almost anywhere.
Tables on Kindle can be problematic. If the table is fairly simple, deal with it in the html. If the table is more complex, a screenshot usually works better. I have not had the chance to look at complex tables on the K3 after the latest update - it may handle them easier.