Stones set on the smallest to biggest diamond ring designs each have one thing in common: their brilliance is affected by the proportions they are cut into. The table percentage is one of the main ones.
A well-cut diamond has a table facet as its largest outer face, through which the light rays entering the stone are refracted. These rays are then reflected back from the pavilion, and into the eye. The table percentage of a stone is the ratio of the size of the table over the average girdle diameter.
This being a large number does not guarantee optimal shine, however. The most fire observed in a fire is usually concentrated on the bezel facets. If the table is too large, it cuts the space at the crown, leaving the les area for the bezel and upper girdle facets. The best look requires the right balance between the light entering via the table, and the color dispersed via the crown and upper girdle.