I can see an elongated oval in it.
Too small for a dining table as is, once trimmed up, IMO
Could slice it through? Super risky.
Could set within an edge frame or plainer timber to enlarge overall, and highlight the elm.
Metal legs. I wouldn't.
Keep it in the workshop for a bit and ruminate.
It's a gorgeous piece of wood, and to bury it in epoxy would be a travesty. I suggest you "sit on it" for a while until the design solidifies in your mind......and, I hesitate to say it, your skill levels catch up with your ambition.
Be aware that elm is not stable. I have a 300 year old piece of elm for my breakfast table, which I made about 20 years ago. It's still moving now.
By way of anecdote competition with fast Mike, 20 years ago, as a beginner in home renovation, I put in a really lovely elm floor in a large bedroom suite. T&G. It looked beautiful. The boards were felled and milled in Dorset and I bought them sight unseen and had them shipped to Surrey. (I was naive then - but the supplier was in fact great). Boy did they move. But they are still there today and listed as a feature of the house. You have to accept it with all wood, but elm especially so.
That is a beautiful piece of wood - I'd definitely mull on it for a bit before I did anything with it. Do you know when it was felled/how long it has been seasoned? (Albeit I agree with the earlier comments that it won't have stopped moving!)
Okay - I wasn't suggesting you should mull it over I was just saying I would.
The round holes are probably common furniture beetle aka woodworm. It's not necessarily anything to worry too much about as if the wood is fully seasoned they will probably have left to look for some damp timber - that's why I was enquiring.
Attaching legs straight to the top without any subframe is unlikely to give the stability you’d want from a dining table, especially as the elm moves. You could still make the frame knock down and then attach the top using buttons
I’m not a fan of Epoxy tables, but many are. Another way would be to rip down the middle and make a recess for a piece of glass to sit in. You could then finish the wany edge just by smoothing over.
I I did something similar with a coffee table using a smaller piece of Yew - I think this is what you mean. Threaded metal inserts work well but ensure you sink them flush and take time to ensure you mark them out correctly as it's easy to get them a fraction out and then they'll miss pre-drilled legs. Finish wise the two best options in my opinion would be Rubio Monocoat or Osmo polyx. Both offer a level of table protection and show the wood's beauty without staining. Osmo is slightly cheaper but as with all finished, prep is key. It's a beautiful piece and will look great.