A similar entry appears in the Wheel of Time Companion confirming the information available in the main story arc.
A Paralis net is a collection of ter'angreal that together make up one piece. Lews Therin was present when the first one was designed and he wore the original version. A full net includes a Well (ToM, Ch. 51). Cadsuane has one as a hair ornament (TGS, Ch. 22).