Because you are using an unbound form, the syntax is a little different.
Table "tbl1Contacts" MUST have field names "FirstName" and "LastName".
Table "tbl1Company" MUST have a field name "CompanyName".
In the code, change the blue text to your control names that are on the form.
Code:
Private Sub save_Click()
Dim sSQL As String
'Append contact name
sSQL = "INSERT INTO tbl1Contacts (FirstName, LastName)"
sSQL = sSQL & " VALUES ('" & Me.txtFirstName & "', '" & Me.txtLastName & "');"
CurrentDb.Execute sSQL, dbFailOnError
'Append Company name
sSQL = "INSERT INTO tbl1Company (CompanyName)"
sSQL = sSQL & " VALUES ('" & Me.CompanyName & "');"
CurrentDb.Execute sSQL, dbFailOnError
End Sub