Try two Fill commands:
Dim query As String = "Select * from Table1"
Using con As New System.Data.OleDb.OleDbConnection(strAccessCon)
Using accessadp As New System.Data.OleDb.OleDbDataAdapter(query, con)
Dim ds As New DataSet()
accessadp.Fill(ds, "Table1 Data")
ds.SelectComamnd.CommandText = "Select * from Table2"
accessadp.Fill(ds, "Table2 Data")
End Using
End Using
Two commands in one works in Sql Server, but doesn't in Access.