Yes, Paul, those are them! Typically, sections are broken off and used as needed.
We still colloquially refer to these as "Choc blocks" or "chocolate blocks," because years ago the plastic was most often black or dark brown rather than translucent (although other colors such as blue and white were available as well).
With the older, more solid types you generally needed to use a sharp knife to cut off however many connectors were needed, but with the newer types pictured above you can just twist them off.
