from gi.repository import Gtk

win = Gtk.Window()
win.connect('destroy', Gtk.main_quit)

grid = Gtk.Grid()

entry1 = Gtk.Entry()
entry2 = Gtk.Entry()

button1 = Gtk.Button('Button1')
button2 = Gtk.Button('Button2')
button3 = Gtk.Button('Button3')
button4 = Gtk.Button('Button4')

buttons_vbox = Gtk.VBox()
buttons_vbox.set_spacing(10)
buttons_vbox.set_margin_top(5)

#buttons_vbox.pack_start(button1, 0, 0, 0)
#buttons_vbox.pack_start(button2, 0, 0, 0)
buttons_vbox.pack_start(button3, 0, 0, 0)
buttons_vbox.pack_start(button4, 0, 0, 0)

sw_child = Gtk.Table()
sw_child.set_size_request(300, 300)

sw = Gtk.ScrolledWindow()
sw.add(sw_child)
sw.set_vexpand(True)

grid.set_column_spacing(10)
grid.set_row_spacing(10)

grid.set_margin_top(10)
grid.set_margin_left(10)
grid.set_margin_right(10)
grid.set_margin_bottom(10)

grid.attach(entry1, 0, 0, 1, 1)
grid.attach(entry2, 0, 1, 1, 1)

grid.attach(sw, 0, 2, 1, 3)

grid.attach(button1, 1, 0, 1, 1)
grid.attach(button2, 1, 1, 1, 1)
grid.attach(buttons_vbox, 1, 2, 1, 1)

win.add(grid)

win.show_all()

Gtk.main()