Avoid Tables and Java script . They screw up keyword indexing. The search engine spiders rip apart tables in illogical ways. Bottom line - Don't put a tables or Java script immediately on the page that you are submitting. If the search engines determine that you are planting unrelated keywords in your Website they can and will ban your site forever from their search index.
Many search engines penalize sites with repeated keywords.
Don't camouflage keywords by making them the same color as your background or putting them in tiny fonts. Search engines penalize sites using this tactic also. Many search engines either cannot read frames or get confused by frames. Engines cannot read these. Don't pay someone else to submit your Website to a zillion search engines.