Grant user access only to specific tables
So this assumes that you have already created the user on the server/database but a simple script should help

USE [Database]
GO

SELECT
 'GRANT SELECT 
  ON [' + schema_name(schema_id) + '].[' + name + '] 
  TO [InsertUser]'
FROM sys.tables 
WHERE name LIKE '%something%';


and run the results in a new query window.  You could probably create a stored proc to do it as well to save for the future and just pass in the user and table name