Is it possible to connect SAP R3 tables without SAP connector?
Sunil jain's advice is correct. instead of connecting to sap over and over you can store the selected table(s) in a qvd file and load those fields from the qvd files to qlikview. if you have changes on those tables(e.g updated some fields or added new data) you can use incremental load so that you don't have to load all the data all over again instead you will load only those modified data or new data. with this process the extraction of data from SAP is faster.