Here is a photo of a lipped shelf I made for under the table storage. If memory is correct, it's 10" wide. It's deep enough that it is supported off the wall bracket as well as the table rails.
I eventually removed the large cumbersome table and went with using a plank platform for bed support (as needed) and I use one of the planks for the shelf.
2012 FR Flagstaff T12SDTH
1996 Shadowcruiser Pop Up Truck Camper
1967 Newell Motorcoach
2003 Ford F150 5.4 V8 Triton Super Cab
2004 Nissan Titan LE 5.6 V8 4x4 Crew Cab