The native Excel reader in QlikView/ Qlik Sense can only read sheets by number (for example LOAD * FROM [./Sales.xls] (biff, no labels, table is @2); ) and not by name.
A solution is to read Excel files via an ODBC connection (for example the default "Excel Files" ODBC connection in Windows), and use SQLTables statement to load the list of sheet names as field TABLE_NAME. Documentation of this script statement can be found on the QlikView help site at SQLTables
Environments:
Qlik Sense Enterprise on Windows
QlikView