2.10.1809 Matthews calls / 28.12.1809 call on Mathews (adv. Young) / 31.12.1809 Listons &c dine; invité Mathews / 18.4.1810 call on Mathews (not seen) / 15.11.1810 dine at Cooper's, w. Incledon, Bellamy, Matthews, Fawcett, Swartwout / 2.12.1810 Cooper &c dine; invités Mathews, Swartwout / 27.12.1810 dine at Cooper's, w. Mathews / 23.11.1813 dine at Poole's, w. Matthews / 2.5.1818 Mathews at Home / 15.4.1819 Matthews at Home / 7.5.1821 Exhibition, adv. Matthews / 13.12.1824 Matthews calls / 7.4.1825 Matthews, Memorandums
All of the above except the two spelt Matthews have been coded in GD website to Charles Mathews DNB 1776-1835 actor but I suggest that the Matthews 1810 at Cooper's should also be coded to him. As with Thomson and Thompson, Godwin didn't always spell consistently, and not only was Charles Mathews a likely guest at Cooper's with Incledon and Fawcett, but the unfulfilled invitations two weeks later were two of the guests at Cooper's - Mathews and Swartwout. The 1809 Matthews calls could also have been Charles Mathews, though this doesn't fit with Mathews' widows' memoirs, that say Godwin first called on Mathews. See the editorial notes for Charles Mathews in GD website. The 1813 Matthews at Poole's was also likely Charles Mathews, as most of the other guests were actors. The 1819 and 1825 Matthews above were clearly Charles Mathews performing, but the 1821 and 1824 Matthews above are more doubtful. Just because Godwin didn't always spell consistently, doesn't mean he didn't try to use spelling to distinguish different people. All those below are Matthews and have initials
15.5.1811 call on W Matthews (not seen) / 16.5.1811 call on W Matthews / 7.7.1815 A Matthews dines / 8.7.1815 M(ary) J(ane), F(anny), W(illiam) & A Matthews for South-end / 7.8.1815 M(ary) J(ane), F(anny), W(illiam), A & B Matthews, & Mulready at tea / 12.8.1815 Curran, Lubey & mrs Matthews at tea / 17.10.1815 M(arshall) dines; adv. mrs Matthews from Hogan / 21.12.1815 A P Matthews calls / 10.9.1816 A P Matthews & P(eter) P(ilcher) dine / 13.9.1816 Mulready & A P Matthews at tea / 15.9.1816 A P Matthews & P(eter) P(ilcher) dine / 21.9.1816 again / 6.10.1816 A P Matthews dines & sleeps / 7.10.1816 A P Matthews dines