Thank you for the tips! I just used 2x's and didn't realize how much the wood would "move". I ripped them pretty well but even after an hour or so I could see significant changes.

In the future I plan on using much better wood at least for the table top, not so much the legs.

Hummingalong2,

I wanted the rustic look but some of the gaps make it look sloppy. Almost to the point of lazy I guess you could say.

I managed to take some pics so you could have some reference, as you can see the spaces are deep and wide as well as irregular.

I'm afraid stain able wood filler would be too dark once I stain the table.

You might try something like this:

https://www.woodmagazine.com/materials-guide/finishes/filling-grain-for-perfect-finishing

There are some epoxy products you could use and insert some stones, like turquoise, however, since this isn't the right wood for furniture, I would just stain it up and let nature takes its course. Any movement in the wood (and there will be some) will loosen any filler you use most likely. Here are some examples.

I'm going to go ahead and fill and stain it. If I don't like it I'll just replace the top with some nicer wood.

The time to address the gaps was when he boards were laid up. The edges should have had the roundness ripped, then been dressed on a jointer, and glued and clamped.

Joseph Corlett,

I ripped the edges and did the best I could clamping. However the wood just started warping and there wasn't much I could do. I glued and used pocket holes but I couldn't get them to square up.

*Update*

I decided to just fill the cracks with wood filler and see
how it turns out. First thing I did was apply some pre-stain conditioner and it
was starting to look really good.

I was surprised to see that the cracks were hardly noticeable
but I was still concerned that once I applied the stain they would darken up
considerably.

I applied the stain and it looks awesome! However, I decided
to try some Poly shades that my brother gave me and I am pretty disappointed.
It was very difficult to match the coverage and made the finish look sloppy. I
don't recommend.

Next time I'll use regular stain.

Came out great considering the challenges. Ditch anything Minwax and go with Old Masters stains. Looks really good in the pictures!

Flyr4fun,

I just looked up Old Masters. Seems like they are promoting some gel stains.

Would you recommend?

I'm building a similar table to use as a kitchen table ... i need to close the gaps . I was wondering how your method worked with humidity change .. Thanks