This requirement aligns to using XPath perfectly.
My list used in this example:

And my Excel Table:

See my full flow below. I'll go into each of the actions.

Get items retrieves all the items from my SharePoint List.

XML is a Compose action that converts the body of Get items to XML so that we can use XPath in the next step. It also adds a root element to ensure its valid XML. The expression used here is:
xml(json(concat('{"root": ', outputs('Get_items')?['body'], '}')))

And finally, we have our Add a row into a table which takes in the following expressions for Color, Day, and Pet respectively. This extracts out each of the values and joins them with a /
join(xpath(outputs('XML'), '//root/value/Color/text()'), '/')
join(xpath(outputs('XML'), '//root/value/Day/text()'), '/')
join(xpath(outputs('XML'), '//root/value/Pet/text()'), '/')

And the output after the flow completes, we have the values joined, separated by /
