Tables measuring 4' x 8' in playing surface are the norm in small rooms where space is at a premium. This size, common for home dens and basements, is less costly than the 4½ x 9's due to their smaller size, but have a key disadvantage (okay, challenge).
The balls, often the same size as on the larger tables, tend to "huddle" together on the smaller table, making it difficult to run the table. Playing on a small table also weakens one’s ability to shoot the cue ball accurately over long distances. The bigger table forces more of an aiming and playing effort.
4' x 8' is a common size for "bar tables", the wonderous inventions in pubs and watering holes worldwide. Payment for table time is on a game-by-game basis, put your quarters (or shillings or dinars) in the coin slots and get the balls to appear. If you scratch the cue ball, it is magnetized due to its unique construction to return via a separate exit for your instant, free reuse. Sink an object ball, however, and it stays down beneath the table surface--until you pay to play again.
Many bar tables use a different (nefarious!) method of returning the cue ball to play. The cue ball is not uniform, somewhat bigger than the rest of the set in size! This presents a challenge for all types of shots, especially those off a rail or jump or draw strokes. An art form in itself, bar pool is a true test of nerves and skill. Be sure if you purchase a used, smaller table for home, that you are getting the type you want to play on at home, a 4' x 8' that returns all the balls to you without forcing play with awkward sized cues... or pool tables sizes.