Is it safe to create new table in CRM 2013 database and insert into that table from plugin?

Hello,

is it safe to create new table in CRM 2013 database from MSSQL Managment tool?

Table will not have any relation with CRM tables and it's sole purpose is to contain composite key of some Primary keys (ID's) of several Entitys.

Is it safe to insert into that table from plugin using plain old ADO.NET SQLConnection class?

Thank you,

Renato