Within the Places system, Pages are a subsystem that: "makes it easier to spread out detail. For example, a Room might contain a grandfather clock, with a link to examine the clock - the link would lead to a new Page within the Room." Pages can also be used in Programs.
Pages cost 20 Wood and 10 Stone resources to build, and then you'll need to Decorate it to create the content.
To create a page you'll need to have job creation permissions for the Place.
Click the Job Creation link under Keybearer Options, then click Create a Page in the list that is presented.