The average cave bear was about the same size as the largest modern-day Grizzly, with males weighing up to 1,300 pounds or so, and females in the 500-pound range. Scientists think they were mostly plant eaters based on the wear of their teeth.
Huge numbers of cave bear bones have been found in southern, central, and eastern Europe, and at one point my father and I seriously discussed (I think we were serious) buying a fully articulated cave bear skeleton (standing) for his living room. It was only $15,000, as I recall, because it was assembled from bits and pieces of many bears -- a collection of detritus made whole. Needless to say, we never quite got our wallets open. He would have paid half if I had ponied up the money, but at the time I simply did not have it.