First two are logs of changes to your upstream channel ID number 10. It went from profile 11 to 12 on 9th May, then went from profile 11 to 12 on 19th May.
Basically logging a change in frequency and/or modulation of your upstream channel number 10. It may sometimes change due to interference/unstable signal. It's a bit like tuning a TV channel, In fact it's exactly like tuning a TV channel as DOCSIS is basically using Cable TV network to "pipe" internet through channels which would typically be used to pipe a TV signal. If one channel is snowy or has bad signal it switches to another channel.
If you go to router stats you can see individual upstream channels and their channel IDs as well as their current frequencies and modulations. DOCSIS connections will bond several "channels" at different RF frequencies to give you the total bandwidth you need.
The last one is a DHCP error, the modem will request some information from Virgin Media's DHCP server and the response received from the DHCP server was erroneous or not received. This error type is typical for VM connections.
Those MAC addresses won’t be any of your Ethernet or Wi-Fi devices, those are the MAC addresses of the RF transceiver in your modem and the RF transceiver at VM's end; the other end of your coaxial cable also known as a "CMTS".
