In the index.php template I want to display posts in 3columns in a table format. How can I do this? I don't want a list format cause I have variable hight image sizes
You still can use lists - just use proper CSS (every third li - first li in every row - should have
If you really have to use table (I don't suggest it - it's not a very good idea, because it's not semantic), you can do something like this:
Not tested it, so it can be a little bit buggy, but idea should be clear.
Basically this can be done with a new WP_Query: http://codex.wordpress.org/Class_Reference/WP_Query
You have to add the markup for your table inside the loop. You should give some more information about the direction you want your posts to appear to create a complete snippet. For example: