I assume you were wanting to do a tung and grove .
this is a table top I made for drawing or working leather or sewing or about any thing but cleaning fish.
It is all tung and grove oak the drawing square is cherry and ash

- 20170307_144849.jpg (144.38 KiB) Viewed 19889 times

- 20170307_144926.jpg (144.06 KiB) Viewed 19889 times
I was care full not to go all the way to the end with the tung and groves so they wouldn't be seen.
A piece of tape used for marking the cuts on the saw and the stock helps so you dont cut all the way through to the end if thats what you have planed ,,,,, then clean up the ends with a chisel .
If that gives ya any ideas .
You are correct about cutting horizontal , you can also do it on the table saw with a dado blade.
Hobbyman2