Ergonomics studies human body measurements relative to the safe use of equipment and furniture. An enormous amount of time and money have gone into designing ergonomically sound office furniture, so productivity isn't compromised, but what about the many hours we spend in the home? Do we think about our families' musculoskeletal welfare when we make that dining room table purchase?The rectangular dining table. Rectangular tables are the most popular shape for dining. Consider the length of table that your room can comfortably fit. Generally, 36 inches between the edge of the table and each wall or other piece of furniture will allow for chairs to be pulled out with ease. If you can, leave 48 inches between the table and the entrance into the room. Having an arched entrance like the one in this picture stops the awkward bunching of people at your door when you announce that dinner is served. Once you know how long your table can be, you can then work out how many can comfortably sit around it. Allow at least 24 inches of elbow room for each guest. These days, no matter what shape or materials are used, the average dining table measures 29 to 32 inches from the floor to the top of the table.