The phrase "upcoming slate" refers to a list or schedule of events, usually in the context of movies, TV shows, or other entertainment content, that will be released or become available in the near future. Full definition
The packed arena presentation was easily the highlight of Day 1 and offered fans a first look at the company's upcoming slate of animated offerings. (pixartimes.com)
The production division's upcoming slate includes co-productions with Luxembourg and Belgium on Bruce MacDonald's Dreamland, Ireland on April Mullen's Bloody Knuckles, and Dolphin Tale director Charles Martin Smith's The Maclean Boys. (dfilmscorp.ca)
UPDATE: Right after I published this, Marvel announced a huge upcoming slate with an updated release date for Doctor Strange, which has been reflected above now. (moviemezzanine.com)