Multiple center pieces can be added to extend the length of the table. The center piece of the 3-piece wooden tables is the same piece as center, type 3 for the 9-piece wooden table.
Center, type 3 is also the center piece for the 3-piece wooden table. Multiple center pieces will be required to complete a 9-piece table. A center piece is also used for the north-west corner of the completed table.
The table can also be expanded in size by adding center pieces, or narrowed in size by placing both corner pieces closer together (or even on top of each other).
Notice that the shadow falls on either the left or the right side of the table legs; you will likely want to keep those consistent within your table.