Two pieces joined that way would only be strong in two axes, but as long as you are supporting it, so it doesn’t bend, it should be fine. You would get more strength in the third axis if you used a spline joint rather than a biscuit or domino when edge jointing the next row of boards together, as the spline would run across the sides of both boards you joint. Breadboard the ends and its fairly easy. If you want the live ends showing, you would have to stop the spline groove before each end of the table top.