I have noticed that when deploying my package, there are some stored procedures created that are not declared in the package. They're not mine.

Those have the form of TableNameInsertIgnore and have an insert statement in them. I can also tell you that there's one for each table that I have a data deployment package for. This should make sence I think.

They're not actually causing any trouble, but I think you should know.

They are "auto-generated" procedures that are defined within the table properties for each of the tables in your package.  Right-click on one of the tables and select "Table Properties" and you will see the checkboxes along the right-hand side that define which CRUD stored procedures you want the DDT to generate.  Just uncheck them and they'll quick being deployed.