There are three different ways to retrieve the TableId from the tablename in Dyn365F&O.
1) Via code
It is possible to create a runnable class and insert the following code fragment:info(strfmt(“%1”, TableNum(PurchTable)));
2) Table browser
Connect to the environment using the following URL
http:///?cmp=usmf&mi=SysTableBrowser&TableName=SysTableIdView
3) Databases
Run the following query against a database in a Dev environment:select * from SysTableIdView