Rhonda,
A table topper is a round or square mat that is used on a table, similar to what a doily used to be used for. I have seen them done in hexagon and round shapes also. Size depends on the size of the table.
A candle mat is a smaller topper similar to a coaster, but large enough to sit under a candle.
Your kaleidoscopes are beautiful. Thanks for sharing your directions. You could certainly use them on anything .... including appliqued to a square for a pillow.