Follow the below steps to get the volume of Tables,

Step 1: Open MSCRM SQL Database.

Step 2: Under Databases, select the required <CRM_Org_Name>_MSCRM database. Right click on it and click on Reports -> Standard Reports -> Disk Usage by Table.

Step 3: Disk Usage by Table report will be displayed as shown below.

Other way to do the same is,

Step 1: Select the required MSCRM database. Click on F7 or View -> Object Explorer Details.

Step 2: Object Explorer will be opened in a new window. Right click on the header to select the required data columns to be displayed as shown below.

Hope you got the results successfully :):):)