There two transformation functions dedicated to working with Excel cells "Get Excel cell value" and "Get Excel cell value dynamic".
They work in a different way. Both of them open the excel file, get cell value, close the excel file. "Get Excel cell value" does it only once therefore it is very fast. However "Get Excel cell value dynamic" does it for every source record. Let assume that the data source has 10000 records. It takes approximately two seconds to open the file. If the transformation has five "Get Excel cell value dynamic" transformation functions. It will take ten seconds to transform a single row an more than one hundred thousand seconds to process the entire data source.
When possible "Get Excel cell value dynamic" should be avoided. Otherwise, move "Get Excel cell value dynamic" into a separate Transformer (Transformer 5) and read the data once. That will improve performance multiple times.
Reading data once: double click on Reader 2 and set read first record/line to 1