Surface

A surface is a type of buy mode object that has appeared throughout The Sims series. It is primarily used to carry small objects like decorations, books, computers and food that normally cannot be placed on the ground. Sims tend to only be able to use objects on a surface if there is a chair next to it.

In general, surfaces are divided into five categories: counters, tables, end tables, coffee tables and desks, though not all games use the same category names. Counters are required for meals that require preparation. Island counters and dining tables can be used as eating surfaces if a stool or chair is located next to it.

Coffee tables and end tables
Sims will typically use end tables for placing unpaid bills, newspapers, and magazines on, and may use coffee tables if there are no suitable end tables nearby. Sims will usually look for coffee tables when putting down a coffee mug, if there isn't any accessible end table around.

Counters
Counters, just like any surface object, can hold small decorative objects. Small appliances and cash registers can only be placed down on and function properly on a counter. Apart from holding things, these objects are also required for the preparation of meals that need require a preparation surface. Meals will also typically be placed on a counter when they are finished. When a pizza is picked up by a Sim or munchie bot, they will leave it on a counter if there is no accessible desk on the lot.

In The Sims 2 and The Sims 4, dishwashers and trash compactors must be placed under a regular counter. This is not a requirement in The Sims 3. In The Sims, dishwashers and trash compactors cannot be placed under a counter and are always standalone appliances, although objects, including plates, can be placed on top of them. A counter that has a dishwasher or trash compactor underneath cannot have sinks placed on them, as there is no room for the basin and the pipes.

Vampires can fly over counters when they have transformed into bats.

Tables
Tables are typically used as dining tables, where Sims will eat their meals whilst sitting at. The number of plates that can be served on a table depends on the size of the table and the number of chairs surrounding it. Sims can eat from the tables as long as there is a chair located next to it facing inward.

Tables can also be used to hold small items, including small decorative objects.

Computers can be placed on and used from a table.

Desks
Desks can be used for doing homework and for placing computers, although Sims will also use them as eating surfaces if there aren't any other surfaces available.