Hi Enrique,
There is more than enough memory to store up to 16,000 MAC address in the bridge (forwarding) table on Catalyst 5xxx series switches.
The recommended baseline threshold is 8,000 entries or 50 percent of the maximum entries allowed per switch. The numbers should be much smaller per subnet or VLAN. Depending on the type of traffic per VLAN, the number of CAM entries can vary. If there is nothing but TCP/IP traffic, 500 nodes may be the limit, whereas on Appletalk segments, 200 may be the limit.