The red bottomed table was fired multiple times the last two times were to fuse the bottom to the top and the last time to get a better finish on the top. Unfortunately this last firing resulted in a cracking of the top. I filled the cracks with gold coloured epoxy after the practice in Japan of repairing favoured cracked cups.
The top and bottom of green table were joined together with a glass tile adhesive that I had used when installing backspash tiles in our main bathroom. This approach seems to be equally good as the fuse firing approach.