Abstract: A portable supporting and stabilizing structure is disclosed that is particularly well suited for securely maintaining a preselected orientation of a utility surface, such as, for example, a work surface, an equipment mounting surface, or a food tray by, and adjacent to, the thighs of a seated user of the utility surface. The structure includes a supporting section for support of the utility surface and a stabilizing section connected with the supporting section and receivable adjacent to the thighs of a user of the structure so that, when force is exerted by the user's thighs against the stabilizing section of the structure, changes in orientation of the surface are resisted thus securely maintaining the position of the utility surface during use thereof. Structures are disclosed which are collapsible and which are selectively configurable for employing inward or outward exertion of the thighs by the user against the stabilizing section of the structure to stabilize the utility surface.