Automatic mapping
This is the default mapping mode. Several things here will depends on your custom adjustments in Project options, like naming and schema and data type mapping.
We will use the closest data types available in target database to represent your source columns. Target table name will be the same as source table name, but limitations of valid identifiers in target database (in length and allowed characters) will be taken into account to make sure we create a valid table structure.
There is generally no need to touch anything, but if you do need to adjust the way table is copied over, you can do a lot here by going with Manual mapping.
You can deselect columns without enforcing manual mapping. Use Deselect all and Select all buttons to quickly change selection on all columns and use your mouse to click on individual selection check boxes from there.