Quite simply, it gives statistics on all the endpoints Wireshark has discovered. It can be any situation, such as the following:

• Few Ethernet (even on) end nodes (that is, MAC addresses), with many IP end nodes (that is, IP addresses)—this will be the case where, for example, we have a router that sends/receives packets from many remote devices.
• Few IP end nodes with many TCP end nodes—this will be the case for many TCP connections per host. Can be a regular operation of a server with many connections, and it could also be a kind of attack that comes through the network (SYN attack).