Hi Steve,
Thanks for your interest in Syncfusion Products.
You need to have a custom MouseController that AutoFills similar to the Excel. If you mouse hover at the bottom right corner of the cell, a cross cursor appears similar to the Excel and you can extend the selection to AutoFill the up/down rows similar to the Excel.
Please check the below sample for more details.
http://www.syncfusion.com/Support/user/uploads/AutoFill%20Non-Contiguous%20Selection_8b754fbd.zipPlease refer our shipped browser samples for forumula support with grid simliar to excel
\\Syncfusion\EssentialStudio\5.2.1.16\Windows\Grid.Windows\Samples\2.0\FormulaSupport\
To have multiple range of cells getting pasted on pressing enter, you need to handle the CurrentCellKeyDown event. Please refer the below sample that shows this working fine similiar to excel.
http://www.syncfusion.com/Support/user/uploads/GC_ScrollIssue_64b6f6f1.zipLet me know if you have any other questions.
Thanks for your patience.
Regards,
Rajagopal