If you wanted to be historically accurate, you'd use a real varnish on the table (with or without staining first). Real varnishes are nothing more than natural plant resins dissolved in drying oils like linseed oil or Tung oil to make these oils dry to a harder film. They're still available, but often from companies that cater to museums which need such materials to be historically accurate for restoration of old furniture:
Linseed Oil Cobalt Varnish - Natural Binders - Kremer Pigmente GmbH & Co. KG
If it were me, I would use a wiping alkyd based polyurethane on it to get the durability you need to provide the best service on a working surface like a table. Also, wiping polyurethane can be brushed on or wiped on with a rag, and it's thin enough to self level very quickly, allowing you to avoid brush strokes.
It's find and dandy to say "We want a rustic look" but the bottom line is that the reason why polyurethane replaced varnish as the clear coat of choice over wood is because it's harder and more durable and you need that on a working surface like a table top to better stand up to wear and tear and stay good looking longer.
Every paint company will use it's hardest paint as a floor paint because you need high hardness to stand up to wear. A harder film will prevent dirt from getting embedded into it underfoot, and that prevents traffic patterns from showing, and that makes the floor look new longer. It's the same with a cupboard shelf or a kitchen table. If you slide something hard and heavy (like a stainless steel or porcelain crock full of stew) across a soft surface, that surface will be scratched. The harder the surface, the less scratching. Simple as that.
You're table will look "rustic" eventually, why hurry the process along by using anything but the hardest coating you can on it. No pioneer would have ever done that. They'd have been HAPPY to have a table made of any wood stay good looking for as long as possible. Not a single one of them would have thought "Hey, let's paint this table with egg tempura paint to make it look like it was made in the 1600's!" They would have used varnish on that table, BECAUSE THAT WAS THE HARDEST AND MOST DURABLE WOOD COATING AVAILABLE TO THEM. If it wuz me, I'd do the same and use the hardest user-friendly coating available to me, too, which would be an alkyd based polyurethane.
Moisture cure, waterborne catalyzed and two component polyurethanes dry harder than:
Alkyd based polyurethanes (which is what traditional hardwood floor finishes are made of)
which dry harder than real varnishes
which dry harder than highly polymerized drying oils like Danish Oil
which dry harder than Tung oil
which dries harder and yellows less than boiled linseed oil
which dries harder than latex paints.
and ALL, except the top one (isocyanate based polyurethanes) and the bottom one (latex paints) transform from a liquid to a solid film through exactly the same chemical process. Post again if you want to know more about that process.