Used motor oil will pop the figure on that elm...course it might not be appropriate for a coffee table.
I use a lot of this stuff.
Mix a third of each. If you want a little more water resistance go heavy on the varnish. Brands not particularly important, I think I like Valspar better than Cabot. I put it in a clean plastic glue bottle and squirt it on. Rub in with a rag and wipe back off after about 15-20 minutes. If ya wait too long it will get tacky and you will have to squirt a bit more on. It will bleed back out, especially on open pore wood like oak so you will have to wipe it several more times or it will cause shiny spots. Reapply every day until ya get 3-5 coats.
The disadvantages are it is extremely labor intensive. Takes a long time to dry and stinks. It does have some water resistance. Just a tried and true oil finish. I use it on hoe handles to furniture.
You mentioned coffee table which brings to mind coffee, water, and alcohol. I might think about a tougher finish than oil.
Since Dodgy Loner did such a good job on another thread Iíll quote him.
Ed, that depends. Much of what is sold as "Tung Oil" is actually thinned polyurethane. If the can says something like "100% Tung Oil", then that's what it is. But if it says something like "Tung Oil Finish", then it's just a thinned polyurethane product. I would advise against using it on a floor, however, simply because you're not getting as much bang for your buck. You can buy plain old polyurethane, thin it 50% with mineral spirits and end up with the same thing (or at least something very similar).
I've used real tung oil in the past...it took forever to dry.
Tung Oil Finish is ok but you can do better by mixing your own, plus its cheaper.
Some manufactures would even use those same ingredients and call it Danish Oil. I used to be a fan of Watco until I found I could do better.
If your really interested get a couple of books on finishing wood. I'm not into it that much, but before a major project with a new finish I'll do a bit of reading. More importantly I test my finish on a piece of scrap long before I'm ready to finish the actual project.