The user configuration page can be accessed via the Configure button in the top left corner and then selecting User Configuration.
You can set user privileges to either Administrator or Normal user. An administrator can view and modify everything, all projects, categories and tables. They are also allowed to set the user configuration for all users.
For Normal Users privileges will need to be set for each table (or a project as a whole). This is done by an administrator.
They can have one of three possible types of access to each table: Viewer, Contributor and Administrator. You can also set a specific access filter on each table, such as [Price] > 2500, allowing the user to only see rows where cell values in the column Price is above 2500.
See more on Access Filters
Viewer: Can only view the table.
Contributor: Can modify the data, such as adding and deleting rows and modify cells. Can not access the table designer.
Administrator: Can modify the table, both design and data.