How do you create table that automatically add or delete rows?

Mailutoronto 

One way is to use VBA in order to achieve this functionality.

In the attached, you will find two tables named "Main" and "Change" where table "Main' contains some records. And once you start adding records in the Change Table, the Main Table will update accordingly.

The Sheet1 Module Contains the following Change_Event Code in it.

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.CountLarge > 1 Then Exit Sub

Dim tblMain     As ListObject
Dim tblChange   As ListObject
Dim n           As Variant
Dim r           As ListRow
Set tblMain = ActiveSheet.ListObjects("Main")
Set tblChange = ActiveSheet.ListObjects("Change")
On Error GoTo Skip

If Not Intersect(Target, tblChange.DataBodyRange.Cells) Is Nothing Then
    Application.EnableEvents = False
    If Target.Column = tblChange.DataBodyRange.Columns(1).Column Then
    
        n = Application.Match(Target.Value, tblMain.DataBodyRange.Columns(1), 0)
        If IsError(n) Then
            If tblMain.DataBodyRange.Cells(1) = "" Then
                Set r = tblMain.ListRows.Add(1)
            Else
                Set r = tblMain.ListRows.Add
            End If
            r.Range(1, 1).Value = Target
        End If
        Target.Offset(0, 2).Value = Date
        Target.Offset(0, 2).NumberFormat = "dd-mmm-yyyy"
    ElseIf Target.Column = tblChange.DataBodyRange.Columns(2).Column Then
        n = Application.Match(Target.Offset(0, -1).Value, tblMain.DataBodyRange.Columns(1), 0)
        If Not IsError(n) Then
            Set r = tblMain.ListRows(n)
            r.Range(1, 2).Value = r.Range(1, 2).Value + Target.Value
            If r.Range(1, 2).Value = 0 Then
                tblMain.ListRows(n).Delete
            End If
        End If
        Target.Offset(0, 1).Value = Date
        Target.Offset(0, 1).NumberFormat = "dd-mmm-yyyy"
    End If
End If
Skip:
Application.EnableEvents = True
End Sub