Hi Sam,
Not sure if I understood your requirement correctly, but are you looking for an option to load the data from Excel file ? If so, you can use the import option in HANA Studio with Data from local file, which allows you to import Excel file to HANA table. After loading, you can use the data in SAPUI5 application and can write back the changes to the database.
Did I get your requirement correct ?
Regards,
Ravi