I can't envision how a sliding dovetail would work on this top which has no apron and a steel base. I'm confused.
I did enjoy the video and the coffee table was beautiful.
Thanks for asking...
Please do let me know it what I am about to write is helpful...I will try to be clear, yet with questioning I will inevitably get better. This isn't really that complicated (bull snot...ha, ha,...I know...
) but seriously, it isn't. Once you get it (and try once or twice) it often becomes the go to solution for such applications...
Grund1019's original design had a glued on 11"x11" plate (since removed wisely enough!) and has a glued up top of Black Walnut. Like in the video, this "glue up" is eccentrically a large slab not too unlike the solid slab in the video, yet probably more dimensionally stable if the grain patterns have been oriented to work in concert with each other.
The original 11"x11" plate represented the area Grund1019 intended to mount to the table top's support stand. It reminded me immediately of Miya San's design for his desk and the size (approximate) to his 4 dove tail toggles.
With this traditional mounting system Grund1019 can create a mounting base upon his current intended support stand. This should probably be made of solid wood, yet I have seen epoxy impregnated HDF board employed as well for more modern looking tables. (Not my recommendation, but others have used it with reinforcement in the slotting.)
On his table top itself he will cut a corresponding mortise (much like in the video.) This can receive a "glued in" dovetail tenon" or a "free floating" dovetail toggle tenon.
I think (hope?) from here you should "get it" or at least be able to ask more questions...If interested.
Thanks again for asking...