Very well done. I hear you on the feeling like you don't know what you are doing. A few questions:

1) Did you look up plans for building a table so you knew how to put in those corner braces, or did you just look at other tables?
2) How are you going to add an extension when the boards on the table top go the long way?
3) Has it cost you 3x what you thought it would yet?
4) Have you gone on a shopping spree buying tools that you've never even heard of before, but are now sure that you NEED?

Finally, in college my parents gave me this solid oak table that was 4" thick all the way through, with legs to match. This table looked like it belonged to King Arthur. We would throw poker parties and the people would pound on the table all night long and no drink would even quiver, let alone spill. It was the best table ever made, and I left it outside on a deck for a year and it was in pretty bad shape when I moved out (and wouldn't fit into my car), so I left it. In short, I'm envious of your awesome solid wood table.