Something like this should work as long as there aren't any nested lists in there:

let
    Source = Web.Page(Web.Contents("canada.ca/en/health-canada/services/drugs-medication/cannabis/industry-licensees-applicants/licensed-cultivators-processors-sellers.html")),
    Data0 = Source{0}[Data],
    #"Changed Type" = Table.TransformColumnTypes(Data0,{{"Licence holder", type text}, {"Province / territory", type text}, {"Licence(s)", type any}, {"Classes of cannabis the licence holder is authorized to sell to provincially/ territorially authorized distributors/retailers", type any}, {"Classes of cannabis the licence holder is authorized to sell to registered patients", type any}, {"Client Care phone numbers for registered patients", type text}, {"Date of initial licensing (year-month-day)", type text}}),
    Result = Table.TransformColumns(#"Changed Type", {}, each try Text.Combine(_, ", ") otherwise _)
in
    Result