Best finish for a dark stained pine trestle table

First, lets modify your stain schedule since pine is a very blotch prone wood.  I would not use the GF dye stain.  It isn't a dye exactly since it contains a water borne binder tinted with stain.  This makes it much or difficult to avoid blotch, and the binder doesn't give much time for work.  I would instead use a powdered watersoluble dye, such as one from W.D.Lockwood or TransFast (not TransTint.)  Applied by flooding on with a sponge it penetrates more evenly and can be tweaked until you get what you want.  You choose the darkness by how concentratedly you mix the dye with distilled water.

Then the dye can be sealed by a blonde dewaxed shellac.  This will be color stable, and the sealing will prevent pigment stain from blotching.  Personally, I would suggest using an oil based pigmented stain.  Waterborne stain dries so fast that you have to be really fast, or better a two person team, to get it applied, and then wiped off evenly.  Oil based pigmented stain gives you enough time to apply it and then wipe it off evenly. 

The multistep program will give a much more interesting finish than just mixing the two stains together.  Done with the red first followed by the dark brown you will get red highlights shining through the brown, not just a red brown color.

I would use a light colored oil based varnish such as Pratt and Lambert 38.  This will provide a very durable finish able to hold up well to use and to frequent cleaning.  You  can thin with mineral spirits to make into a wiping varnish if you like.  It is much lighter than many other varnishes, and compared to the other choices polyurethane varnishes and Waterlox varnish, will yellow less over time.  Acyrlic waterborne finishes yellow very little, but are not as resistant to household cleaners that might be used on a kitchen table.