Just import the plugin into a application and on a page with a File Browse item add the plugin to the "processing" section at that page As soon as you submit your page the Excel is loaded to a APEX ...

ExcelTable is a pipelined table interface to read Excel files (.xlsx, .xlsm, .xlsb, .xls, .xml), ODF spreadsheet files (.ods), and flat files (delimited or positional) as if they were external tables.