The PK51 and PK55 tables were designed by Poul Kjærholm for Fritz Hansen in 1957 and are two rectangular tables, the PK51 being the larger model and the PK55 the smaller one. The table has an ash veneer top, and a base made of a steel frame with four legs in satin-brushed stainless steel. PK51 was the first of the two tables to be introduced and was presented together with the PK11 chair in an exclusive matching set.

PK51 and PK55 have a pared-down design that can easily be combined with the PK11 chair, which has a more intimate design. Kjærholm's use of different materials and contrasting shapes creates a harmonious balance between hard and soft.