When using the Load Data and Transform Map process, what is the Mapping Assist used for?
The mapping assist utility provides a visually intuitive environment for specifying mapping between import set fields and production table fields. The mapping assist utility makes it possible to map a single source field (field on an import set table) to multiple destination fields (fields on a production table).
https://www.servicenow.com/docs/bundle/xanadu-integrate-applications/page/script/server-scripting/concept/c_MappingOptions.html