Here at the beginning of verse 5, Oliver Cowdery initially omitted the and. Somewhat later, perhaps when he read the text back to Joseph Smith, he supralinearly inserted the ampersand with somewhat heavier ink flow; the insert mark itself has even heavier ink flow and appears to have been written very quickly since it looks more like an x than a caret. The and seems needed here, so conscious editing cannot be ruled out. There is, however, considerable evidence in this chapter that Oliver tended to omit the and in 𝓞. Later on in this chapter, there are two examples of sentence-initial and that Oliver momentarily omitted in 𝓞 (and supralinearly inserted almost immediately):
Summary: Accept in Alma 46:5 Oliver Cowdery’s inserted and in 𝓞 as the reading of the original text.