Thanks for sharing and very cool. That's a very interesting way to hog out the material and you did a really good job all said and done taken I assume the dremeling had to be done by hand.
If you are interested, this is the style of bit I'm hoping to get. I'm not sold on this brand as it seems you'll get mixed results if you are doing heavy work, but for a handful of depressions in stuff that's not going to be heavy duty hardwood, I hope it's going to work out. Not sure what types of equipment you have but I do own a drill press which I would plan to use with this. If you plan on making more, maybe this could save you some time and elbow grease?
Thanks for sharing and hope you enjoy your table.
Yonico 16170 Small Bowl Router Bit with 1.65-Inch Radius, 1-3/4-Inch Wide and 1/2-Inch Shank https://www.amazon.com/dp/B00KZM2UEW/ref=cm_sw_r_cp_apip_744ITrax1eUVP
As for the speed I'm not home but it was fairly slow like 1000 rpm. I also used pine on purpose cause it being so soft. That bit is not the greatest.
Looks like a horizontal crown bit. This one is a 1.5" radius curve and 1.5" diameter cutting surface.
https://www.amazon.com/dp/B00KZM2UEW/ref=cm_sw_r_apa_i_X3CPSNAD3BSRNTFSKXGK_0