There is a simple trick to uncovering this function.
1. You simply have to add minimum 2 levels to your course. To add a new level to your course, scroll down to the bottom of your word list and click on the 'Add level' button.
2. After having added a new level, the 'Databases' tab will appear between the 'Levels' and 'Contributors' tab.
Related articles: What is a Database?
What can be edited in a database?
Would you like to create a course in Memrise? Find out how to Create a Course.