Coffee table height
The useful comparison is the height of the sofa cushion. A table level with the cushion or a little below it is easy to reach down to; one much higher starts to read as a dining surface and one much lower asks you to lean.
That is why a twelve inch table and a twenty three inch table are not two sizes of the same thing. Low tables suit deep modern sofas with low cushions; the taller end suits upright seating, where a low table would be out of reach. Measuring the cushion before looking at tables removes most of the range in one step.
Shape and the seating layout
The tops here are rectangles, squares and rounds. A rectangle suits a sofa with a chair or two facing it, since everyone reaches the same long edge. A square suits a symmetrical arrangement with seating on more than one side.
A round has no corners, which matters in a circulation route and around small children, and it suits a seating group that is not square to the room. The lengths run from around sixteen inches for the smallest pieces up to fifty for the largest, which is the other half of the shape decision.
Marble seen from above
A coffee table is seen from directly above and from a few feet away, seated, in the ambient light of the room. That is a closer and flatter view than a countertop gets, which is mostly read at an angle and under directed light.
It matters because the figure in the stone is read whole instead of glimpsed. A quiet stone or a travertine settles into a room at this distance; a bold Calacatta becomes the thing the seating is arranged around, which is exactly why people choose one.
The marble top as the design
On a small piece the stone is not a surface with a design around it, it is the design. A single bold vein across a forty inch top is the piece; the same vein across a kitchen island is one element among many.
It means a stone that looks busy on a slab page can be exactly right here, and a quiet stone that would disappear in a kitchen can carry a table on its own. The marble page covers what each stone actually looks like.
Nesting and paired tables
Some of this range is sold in twos: nesting tables that tuck under each other, and pairs meant to stand together in front of a long sofa. Both solve the problem of a single table that is either too small for the sofa or too large for the room.
A pair also gives the room two surfaces to place and not one, which suits a seating group that is not symmetrical. For a room that gets rearranged, that is the more adaptable answer.
Coffee table or side table
These two get shortlisted together more often than any other pair here, and what separates them is not size. A coffee table serves everyone around the seating group. A side table serves one chair.
The marble furniture page sets out how the four formats divide and how the stones behave in a living room.