Thanks for considering Aspose.
1). Well, you my try to use Cells.ExportDataTable() or Cells.ExportDataTableAsString() method to export the worksheet's data to fill a datatable. Later you may insert/update you SQL Server database table(s) using ADO.NET components.
//Instantiating a Workbook object
Workbook workbook = new Workbook();
//Accessing the first worksheet in the Excel file
Worksheet worksheet = workbook.Worksheets;
//Create a new workbook for opening the template file
//From which I fill up a data table
Workbook wb = new Workbook();
//Creating a file stream containing the Excel file to be opened
FileStream fstream = new FileStream("d:\\test\\MyFile.xls",FileMode.Open);
//Opening the Excel file through the file stream
//Extract data from the worksheet and fill a datatable.
DataTable dt = wb.Worksheets.Cells.ExportDataTable(0,0,wb.Worksheets.Cells.MaxDataRow,wb.Worksheets.Cells.MaxDataColumn);
2) I think you may read the spreadsheet using Workbook.Open() method and use Cell.StringValue, Cell.IntValue, Cell.Value etc. properties to read/get data in the cells and update your table accordingly.