hi
Loading master data into a DSO can be done using the following steps:
1) Right click on the DSO and select Create transformation... option.
2) In the dialog box that appears, select Object Type as InfoObject and in the text box right below you give the name of the object.
3) In Subtype of Object selection, select attribute or text as per your needs.
4) select ok and you should see the transformation, map and activate the transformation.
5) create DTP and run it.
Hope this helps,