Some neat effects can be obtained with table borders using styles. The px determines the size. The higher the number the larger the effect. The samples below are done in 10px and 20px.

Dashed - 10 px

Dashed - 20 px

Dotted - 10 px

Dotted - 20 px

Double - 10 px

Double - 20 px

Ridge - 10 px

Ridge - 20 px

Groove - 10 px

Groove - 20 px

Inset - 10 px

Inset - 20 px

Outset - 10 px

Outset - 20 px