The table size of round brilliant cut diamonds greatly affects their face-up appearance. No matter how fine the material and how carefully polished it is, a single stone with a mismatched table size will detract from the total beauty of a jewelry piece.

Until the 1960s, the table size of modern round brilliant cuts was usually greater than 65 percent. In the 1980s, the number of those with tables of about 60 percent increased, and since the 1990s, diamonds with table size of about 55 percent (cut with high crowns) are seen in the marketplace. Small tables result in stronger dispersion, but brilliance is sacrificed. Meanwhile, larger tables have the advantage of making diamonds of the same carat weight look larger, and in Europe they are considered to have strong and beautiful brilliance. There is no table size that can be considered the absolute best- quality depends instead on the character that the cutter gives the diamond.

Some diamond grading reports include comments on the superiority or inferiority of a diamond’s cut. The optimum table size depends on how each diamond is taken advantage of in jewelry, so there is no need to be too particular about the cut grade shown in a report. Unless the table is extremely large or small, it is not possible to say whether the cut is superior or inferior.