The following objects exist in Microsoft Dynamics NAV:
Table: describes how data is stored in the database.
Page: displays for example tabular data so users can create, read, update or delete records.
Report: prints information or manipulates data via so called processing-only reports.
Codeunit: an organized unit of code that can be reused by other object types.
Query: defines a relational datamodel for direct querying trough OData for example.
XMLport: with an XMLport you can import and export data in plaintext or XML.
MenuSuite: the MenuSuite describes how the menus should be displayed in the Windows Client.
With the Object Designer which is part of the Development Environment you are able to create, edit, delete or modify NAV objects. Please bear in mind that your license is probably preventing you to modify certain objects and other ‘Development’ tasks.