The Standard Height
Most pre-made dining room tables are 29 to 30 inches in height. This height should allow for adequate leg room and comfortable eating. Anything lower will result in "cramped legs" and anything higher will not be comfortable for dining.
Although your dining room table should be the right size at 29 to 30 inches, there could be reasons for you customize your table height. If you or someone in your family is particularly tall, then 29 to 30 inches might still result in cramped legs. In that case, having a customized 32-inch-high table would work better for your needs.
Unless there is some compelling reason to have a customized table built higher, sticking to the 29- to 30-inch rule should provide you a comfortable dining experience.