I think you have one of the very hard to find table 311. It's not for a FW or a 301/401 but intead would hold the base of a full size machine like the 201 - or the 3/4 size depending on the cutout.
http://www.ismacs.net/singer_sewing_...313_table.html
I've never seen a real one before!!!
However, it does you know good if you want one for a FW.
HEre is the FW table
http://www.ismacs.net/singer_sewing_...308_table.html
And the 301 long bed
http://www.ismacs.net/singer_sewing_...umber-314.html
And short bed
http://www.ismacs.net/singer_sewing_...0-500-301.html
If you don't want this table - send me a PM