I use the following to search for strings in my stored procedures:
use DBname SELECT Name FROM sys.procedures WHERE OBJECT_DEFINITION(OBJECT_ID) LIKE \'%xxx%\' <
If you want to look in all tables in all Databases server-wide and get output you can make use of the undocumented sp_MSforeachdb procedure:
sp_MSforeachdb 'SELECT "?" AS DB, * FROM [?].sys.tables WHERE name like ''%Table_Names%'''