compare delete and sort the data in excel with two sheets

I am guessing at what you want your result to look like since you did not provide a mocked up solution. Here is a solution using Power Query

let
    T1= Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    T2= Excel.CurrentWorkbook(){[Name="Table2"]}[Content],
    MQ = Table.NestedJoin(T1, {"Student ID"}, T2, {"Student ID"}, "T3", JoinKind.FullOuter),
    #"Expanded T3" = Table.ExpandTableColumn(MQ, "T3", {"Student ID", "Name", "Mark1", "Mark 2"}, {"Student ID.1", "Name.1", "Mark1.1", "Mark 2.1"}),
    #"Filtered Rows" = Table.SelectRows(#"Expanded T3", each ([Student ID] <> null) and ([Student ID.1] <> null))


in
    #"Filtered Rows"

Please show expected results.

Power Query is a free AddIn for Excel 2010 and 2013, and is built-in functionality from Excel 2016 onwards (where it is referred to as "Get & Transform Data").

It is a powerful yet simple way of getting, changing and using data from a broad variety of sources, creating steps which may be easily repeated and refreshed. I strongly recommend learning how to use Power Query - it's among the most powerful functionalities of Excel.

- Follow this link to learn how to install Power Query in Excel 2010 / 2013.

- Follow this link for an introduction to Power Query functionality.

- Follow this link for a video which demonstrates how to use Power Query code provided.