How to create a custom table containing data to be rendered using the Views module
Data module helps you model, manage and query related sets of tables. 
The Data module provides


an API for dynamically allocating tables for single-row records.
an API for insert/update/delete operations and describing how tables join to each other.
automatic views integration.
a way to export table definitions to code.


Also next patch in "Describe and use external database tables using Data." allow use external DB tables to show on Views.