The Marvel Star Wars comic finished up in 1986, then Blackthorne published three 3D comics between 1987 and 1988 (based on the Blackthorne comics I have read, I assume these were shit), and then Dark Horse picked up the license and published Dark Empire in 1991, which was a smash hit.
On the novel front, there were very few original books in the same timeframe. Brian Daley (one half of the writing duo Jack McKinney. James Luceno, the other half of the duo would start writing Star Wars novels in the early 2000s and is still going today) did a Han Solo Trilogy between 1979 and 1980, there was a Lando Calrissian Trilogy in 1983, and then there were novelisations of two Droids stories, and one more Brian Daley novel, telling the story of what happened at Ord Mantell - as mentioned in Empire. Again in 1991 Star Wars novels exploded into popularity with the release of Heir to the Empire, the first volume of the Thrawn Trilogy.
The major print item that kept Star Wars in the public eye in the interbellum between the drop-off in popularity in 1986 and the resurgence in 1991 was the Role-Playing Game by West End Games. The first edition came out in 1987 and was a huge seller.