I hate to be disagreeable but I still think it was “grain painted”.
Looking at the top, it appears they started in the “center” and worked to either side, …. as can be noted by the “dark” edge of the grain always being toward the center.
And ps, it is just as easy to “grain paint” both sides and the edge pieces ….. and then the better looking “surface” can be selected for the table-top.
On a production line, …. the grain painters and the assemblers are two different groups of workers.