SQLServer - how to move tables between instances? I'm not very familiar with SQLServer and, thus, I inadvertently created a database in a fashion I thought it would work.

In SQL Management Studio, I right clicked the instance and created a xpto database, so all my tables are xpto.tableName instead of dbo.tableName.

Should I expect performance issues?

Also, is there a somewhat safe way to move tables from xpto to dbo?
First of all if your object names are xpto.tablename you probably created a schema not a new database.

Schemas are the containers for objects such as tables.  Databases contain schemas.  So the naming format is databasename.schemaname.tablename.

Assuming that is correct it's very easy to change the schema that owns your tables using ALTER SCHEMA.

ALTER SCHEMA dbo TRANSFER schemaname.tablename


This will transfer TableName into the dbo schema.  Or a little closer to your specific case

ALTER SCHEMA dbo TRANSFER xpto.tablename


If in fact your tables are in the wrong database you can move them by using something like this:

USE correctDBName
SELECT * INTO xpto.dbo.TableName FROM tablename


You'll then want to generate any indexes, constraints, permissions etc and apply them in the correct database.

Edit

Here is a query you can use to construct the commands to transfer all the tables from the xpto schema to the dbo schema.

SELECT 'ALTER SCHEMA dbo TRANSFER xpto.' + quotename(tables.name)
FROM sys.tables
JOIN sys.schemas
    ON sys.tables.schema_id = sys.schemas.schema_id
WHERE sys.schemas.name = 'xpto'