I'm going to assume they are for the rubber seals on the fixtures.. You want some kind of lube on seals to help them last longer and help them seal.
i wish it said that in the in instructions, as my first big job installing 12 G 40 spot all brass lights...5 failed within a mouth due to water intrusion. but VOLT did replace them with out question. one reason i use volt, just for that VOLT stands behind there products. would be nice if that part was done at factory with the integrated led fixture.