The latter: 1841. (Not 1840; Theodorich's very helpful table is a little hard to read, since the text aligns with the lower edge of the image, not the top)
From what I have been able to cobble together about the 19th century Kahles from Dresden city directories and vital records, it appears the patriarch was goldsmith Carl Adolph Kahle (ca. 1839-1799), He had four sons, all gold & silversmiths:
Carl August Kahle, listed 1809-1843: born ca. Aug 1773; married 14 Jan 1801 to Christiane Friederike Ulbrichs; died 24 Apr 1843
Johann Adolph Kahle, listed 1809-1837: baptized 8 Aug 1774; married 23 May 1813 to Johanna Rosina Nitzsche; Died 16 Nov 1837
Johann Heinrich Kahle, listed 1820-1840: born ca. 1776; died 14 Dec 1840
Christian Gottlieb Kahle, listed 1816-1817: baptized 30 Jul 1782; buried 22 Jan 1816
Even though Johann Adolph Kahle died in 1837, Dresden directories show his widow, Johanna Rosine Nitzsche, operatinng the firm of J.A. Kahle at the same address, 3 Meissnergasse, until her death on 1 Oct 1850 at the age of 74. It appears your spoon was made during the steawardship of the widow Kahle.
The Kahle dynasty of silversmiths continued with Carl August's son Carl Moritz Kahle, listed 1831-1866: baptized 8 May 1802; married 26 Nov 1832 to Adolphina Elenora Claudius; died 23 Aug 1866
Hope this helps!