I've expanded this layout by getting a 30" by 6' folding table. These can be found in the $30-$40 range. While standard T-Trak modules will result in a configuration either too short or too long for a 6' table, Masterpiece Modules, which I use, offers a 1-1/2 length module that will result in a configuration that, in combination with two end caps and a pair of double-length, will fit on a 6' table.
Here are the two 1-1/2 length modules inserted into the previous Phase I layout:
Here is Amtrak 448, the eastbound Boston section of the Lake Shore: