Each form that's created in CampSite can accept (1) uploaded file, so all of the pages of the form need to be saved as (1) file. If each page is saved as a separate file, the user will only be able to upload one page of the form.
If needed, you can also create a separate form for each page of the document being uploaded. For example, for a 3-page waiver form, you could create 3 forms: "Waiver - Page 1"; "Waiver - Page 2"; and "Waiver - Page 3". Parents/staff would upload the respective page into each form. Note that when downloading or printing submissions, the pages will not be collated.