After combining all six pieces by using 4 biscuit joiners and tons of glue on each side, I had a tabletop like surface. However, there were still some gaps in between because the biscuits need at least three hours to expand when soaked with glues. Thus, Nell showed us the demo of how to use clamps to make everything nice and tight. When I was trying to adjust the clamps on sides of our woods and align the clamps with the locations of biscuit joiners, I had a hard time to make six pieces of wood on the same horizontal line. Thanks for Nell helping me by using a mallet and hitting every piece against the ground to make them line up neatly. This is important in the early stage in case the glue gets more sticky and biscuit joiners become larger that there will not have any space to adjust.
I am really happy with the outcome of this table top. Now I will just leave it alone for some time and let biscuit joiners expanding to firmly join pieces together.