Hi,
Full User License: It provide users full read and full write capabilities to all of the licensed solution functionality through any and all modes of access, including the Microsoft Dynamics NAV Windows client, the Microsoft Dynamics NAV Web client, or any other mode of access including web services.
Limited User License: Limited users can only modify up to 3 tables. But any table described in Appendix A of the 'Licensing Guide' as 'Limited User Included Tables' do not count towards the 3 table objects, such as Reservation Entry Table 337, Change Log Table 405, Warehouse Shipment Header and Line Tables, and quite a few more.
Please refer the licensing guide for more details about Appendix A included Tables.
docs.microsoft.com/.../license-types