This DIY outdoor dining table with built-in cooler was made from giant cedar 6×6 beams during my trip to Joshua Tree, CA. The material for this build is definitely not on the cheap side.
source/image(PrtSc): Fix This Build That
But you could substitute pine 4×4’s for a similar look and a really cool wood dining table. Like I mentioned in how to build instructions. Watch the video from Fix This Build That for more info:
I would definitely recommend drilling smaller holes to join tabletop together. I think ⅞” holes and a ¾” all thread would be a great combination for a really stout outdoor table as long as you put the washers in to allow for drainage.
If you wanted a seamless top you could remove the washers and cut or joint off the rounded edges for a smooth beefy top.