Report on All MAC addresses on Network

This will highly depend on the products installed.  If you just have Network Performance Monitor (NPM), then you can execute a SWQL query on the Orion.NodeMacAddresses table.  That can be joined to the Orion.Nodes table to get the caption and IP Address used for polling of the node (not necessarily the IP bound to that MAC address).

If you have IP Address Manager (IPAM), User Device Tracker (UDT), Network Configuration Manager (NCM), or Server & Application Monitor (SAM), there are additional tables you can pull other tables for this information and make a more comprehensive list of hardware addresses, but each report will pull from different tables and change the complexity, but increase the detail.

SELECT [Node].Caption
     , [MAC].MAC
     , [Node].IPAddress
FROM Orion.NodeMACAddresses AS [MAC]
-- There is no Navigation Property to connect Orion.NodeMACAddresses to Orion.Nodes
-- so we need to use a JOIN statment
INNER JOIN Orion.Nodes AS [Node]
  ON [MAC].NodeID = [Node].NodeID
-- Only show MAC addresses that have been registered in the last day
WHERE [MAC].DateTime >= GETUTCDATE() - 1

Long story short, there are dozens of places that MAC Addresses are tracked in the data because there are dozens of places where you need that data for different things.