The main sections of the top navigation of the Snowflake Web Interface (UI) include 'Databases', 'Warehouses', and 'Worksheets'. The 'Databases' section allows users to manage databases, the 'Warehouses' section is for managing virtual warehouses which are used for compute resources, and the 'Worksheets' section is used for running SQL queries. 'Tables' is not a main section in the top navigation, but rather part of the database structure itself. Therefore, the correct answers are 'Databases', 'Warehouses', and 'Worksheets'.