At the bottom of the page is the listing of the bookstore of the newspaper printer, that has guitar sheet music for sale.
Several paragraphs above this is the listing of 14 slaves for sale, with the sexes, ages, abilities of work to be provided and lastly the prices.
Cuba stopped officially participating in the slave trade in 1867 but the institution of slavery was not abolished on the island until 1886. The demand for cheap labor never abated of course, and plantation owners sought other ways of obtaining workers.