Making a pool table with ROUND pockets instead of square pockets by using
    the Mesh menu Boolean Difference command.

 1. Make a Polygonal Cube instead of a Polygonal Plane for the pool table
    surface, if you want to have round holes instead of square holes for 
    the pool balls to fall into.

    What would happen if we use Polygonal Plane instead of Polygonal Cube?
    The results of the Boolean Difference operation are different.

    I used Width 18, Height 0.2 and Depth 10 for my pool table.
                
    For the square holed pool table done on March 4th, I used 16 and 10
    for the dimensions of the Polygonal Plane.  Recall that planes have
    no height or thickness.

 2. Create a Polygonal Cylinder.  I made the default size Cylinder, which
    has a radius of 1 and a height of 2.  The height is pretty much
    irrelevant.

    I used Snap to Grid to place my Polygonal Cylinder right on a grid
    line intersection.

    Now, look at the TranslateX, TranslateY and TranslateZ values in 
    the Channel Box.
                       TranslateX  9
                       TranslateY  0
                       TranslateZ -5   were the settings I saw.

    Duplicate the Cylinder 3 times and change the location of the
    duplicated cylinders as follows:

                       TranslateX  9    -9  -9   9
                       TranslateY  0     0   0   0
                       TranslateZ -5    -5   5   5
                                        --- --- ---
    Now you have the four corners of the pool table.  You are certainly 
    welcome to make the two additional pool table pockets if you wish to.

    VIP NOTE: The above numbers were NOT good at all.  The 1/4 circle
              cutout did not look nice or natural.  I visually found
              where I wanted the pool table hole to be on the 2nd try,
              and then duplicated that 3 times and reset the channel
              box values to place the 3 duplicates.

 3. Select the pool table surface, shift select the pool table cylinder
    for one of the corners.

    Polygon menu set, Mesh menu, Booleans > Difference

    The 2nd object that was selected will be deleted and the places where
    it intersected with the 1st object selected will also be deleted in 
    the first object.