Start from the sitting position
Sit in the chair or at the end of the sofa where the table will be used. Reach to the side as though placing a glass down, keeping your back in its normal position. This identifies a useful area more accurately than centring a table in the gap between furniture and wall.
The arm changes the task. A thick or high sofa arm may make a low table awkward to reach, while an armless chair allows more freedom. Test a surface at approximately the proposed height before shopping. You are looking for a comfortable movement, not trying to match every tabletop in the room.
Leave room for the objects
A narrow pedestal may look sufficient until a lamp takes most of its top. Measure the lamp base and add the space needed for a book, glasses or a mug. If the table is intended mainly for drinks, a floor lamp elsewhere may be a better partner than a large table lamp occupying the whole surface.
Look underneath too. A lower shelf offers storage, but it may make the table feel heavier or catch a foot beside a recliner. A C-shaped table needs enough clearance beneath the seat for its base; do not assume it will slide under a low sofa. The floor should support the table steadily in its intended position.
A table between two chairs has to serve both. Rotate it or adjust the chairs until neither person has to lean behind their shoulder. If that cannot be achieved without crowding them, use separate smaller surfaces or accept that one shared table is not the right arrangement.
Compare the top's finish with the job it will do. A surface used for drinks needs care appropriate to its material, and a textured or uneven top may not hold a glass steadily. A coaster protects some finishes but cannot correct an unstable table.
Keep it out of the journey
The easiest table to reach can sometimes sit directly in a walking route. Move the seating slightly before compromising that route. A surface that is repeatedly knocked or pushed away will not stay useful. Finish by checking the table from the doorway and from the chair: it needs to fit the room when nobody is sitting there and remain convenient when somebody is.
