In continuation from here

We already covered here how to create the form, set references and place the required buttons.

Adding and Deleting sheets in Excel is very simple.

Consider this code. I am also using the DoesSheetExist Function from here to demonstrate the naming of a sheet when you add a new sheet.

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    Dim NewSheetName As String = "MyNewSheet"

    '~~> Opens an exisiting Workbook. Change path and filename as applicable
    xlWorkBook = xlApp.Workbooks.Open("C:\Tutorial\Sample.xlsx")

    '~~> Display Excel
    xlApp.Visible = True

    '~~> Add a new Sheet
    xlWorkSheet = xlWorkBook.Sheets.Add

    '~~> Check If "MyNewSheet" sheet exists using a function and it doesn't exist then rename the
    '~~> above added sheet to "MyNewSheet"
    If DoesSheetExists(NewSheetName) Then
        MessageBox.Show("The sheet " & NewSheetName & " already exists. Please select another name.")
    Else
        xlWorkSheet.Name = NewSheetName
    End If
End Sub

Public Function DoesSheetExists(ByVal shtName As String) As Boolean
    Dim xs As Excel.Worksheet

    DoesSheetExists = False

    '~~> Loop through the all the sheets in the workbook to find if name matches
    For Each xs In xlWorkBook.Sheets
        If xs.Name = shtName Then
            DoesSheetExists = True
            Exit For
        End If
    Next
End Function

To delete sheet, use this code.

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    Dim NewSheetName As String = "MyNewSheet"

    '~~> Opens an exisiting Workbook. Change path and filename as applicable
    xlWorkBook = xlApp.Workbooks.Open("C:\Tutorial\Sample.xlsx")

    '~~> Display Excel
    xlApp.Visible = True

    '~~> Add a new Sheet
    xlWorkSheet = xlWorkBook.Sheets.Add

    '~~> Check If "MyNewSheet" sheet exists using a function and it exists then delete it
    If DoesSheetExists(NewSheetName) Then
        xlWorkSheet.Delete()
    Else
        MessageBox.Show("The sheet " & NewSheetName & " Doesn't exists. Please select another name.")
    End If
End Sub

Public Function DoesSheetExists(ByVal shtName As String) As Boolean
    Dim xs As Excel.Worksheet

    DoesSheetExists = False

    '~~> Loop through the all the sheets in the workbook to find if name matches
    For Each xs In xlWorkBook.Sheets
        If xs.Name = shtName Then
            DoesSheetExists = True
            Exit For
        End If
    Next
End Function