Can members help me explain what is going on here?
Looks like they consolidated various inputs into one larger output. Perhaps they did it during a low fee period.
If it's of importance, how can it be done on a normal wallet like electrum?
Most people don't have a reason to do this. Your wallet will automatically draw from these inputs when it needs to so going out of your way to do it is normally not required or cost effective.
If you really want to do it right click on the address in question on the addresses tab and choose spend from. Then click on max on the send tab to spend the entire amount i.e. all unspent outputs sent to that address.