Due to the myriad of possible monitor sizes and resolutions, then add zoom factors to the equation, a maximum form size in Base is an illusive target.
Base forms do not directly support multiple pages.
In my experience, when there are more form controls than will fit on a screen, the first thing to look at is if the database tables are normalized. Often, normalization will allow some fields to be moved to other database tables and displayed on SubForm table controls with scroll bars.
A Base Handbook can be downloaded from
https://documentation.libreoffice.org/en/english-documentation/base/beyond that, look at the Tutorials and Examples areas of this Forum.
If your problem has been solved, please edit this topic's initial post and add "[Solved]" to the beginning of the subject line
Apache OpenOffice 4.1.8 & LibreOffice 6.4.7.2 - Windows 10 Professional