What you request could be fairly simple. The problems however lie with your statement "Then I'd need to loop the macro to run again for the next set of tables." and the content of the last cell in table 3.
Do we assume that there are several blocks of four tables in the same document, each to be treated similarly?
If the following, which assumes there may be blocks of 4, but cannot identify the content of the cell in table 3, doesn't work for you, post a link to a sample document.
Sub Macro1()
'Graham Mayor - https://www.gmayor.com - Last updated - 21 Oct 2021
Dim oTable As Table
Dim i As Long, j As Long
If Not ActiveDocument.Tables.Count Mod 4 = 0 Then
MsgBox "The document has tables that are not in groups of 4", vbCritical
Exit Sub
End If
For i = ActiveDocument.Tables.Count To 1 Step -4
Set oTable = ActiveDocument.Tables(i)
For j = 3 To 1 Step -1
oTable.Columns(j).Delete
Next j
Set oTable = ActiveDocument.Tables(i - 1)
oTable.Rows(1).Delete
oTable.Columns(1).Delete
ActiveDocument.Tables(i - 3).Delete
ActiveDocument.Tables(i - 3).Delete
Next i
lbl_Exit:
Set oTable = Nothing
Exit Sub
End Sub