SpreadsheetGear provides a method IWorkbook OpenFromStream(Stream stream); to read in a file via a Stream. Does this read in the entire file immediately or is it possible to access values a row at a time?
SpreadsheetGear reads a workbook file in its entirety, regardless of whether the file is opened via file, stream or byte array. There aren't any options that would allow you to read in some portion of a file.