Yeah, the pine from Lowes was actually really, really nice. I was very surprised about that. It was virtually knot free and straight.
The table is 30"D x 48"W x 18"H. The table top is 3/4" pre-made pine that I also bought at Lowes. I had to buy two of them and rip one to length. I used biscuit joints to connect them along with glue (obviously). I did over engineer the legs too. They're pocket-screwed to the table top, screwed into the top (hidden by the black corner protectors), and also carriage bolted to the styles. Like I said, they're really really strong. I made a few mistakes but overall I'm happy with the result. My son loves it.