Merge 2 tables using similar data to match

Ironpixel , Try a new column in Dax Like this

maxx(filter(Table2, search(table2[Team Number], table1[eam Number],,0)>0),Table2[Team Name])

Hi, Ironpixel , you might want to try such a solution,

let
    Lookup = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("fc47CoAwEATQq8jWgSXsN6W/G9iFFBaW3r81opIiYDcMj2Fyhu3Yz2GEABhJTFBdiB09aYoEJbxi6kQkV25gfoCJfUDZqWYmxaRO1uzSj3kVdyXa2Po3SV4PQCkX", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Team Name" = _t, #"Team Number" = _t]),

    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("fcuxCgJBDIThd0l9EMIk2dnWwsJXWLY7wYPjBN+/MJ7Y2gQy/N8Ycns+DllEDdFCkwGnsmc3KJiEZhCuXk/KXIZcX/f1K1q0n0j/lHSk9kJNYQTPe6LLtu//EGiVOyzZa4JVWZPM+QY=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"User Name" = _t, #"Team Number" = _t]),

    Matchup = Table.AddColumn(
        Source, "Team Name",
        each List.Accumulate(
            Table.ToRecords(Lookup),
            {[Team Number], {}},
            (s, c) => if Text.Contains(s{0}, c[Team Number], Comparer.OrdinalIgnoreCase) then {s{0}, s{1}&{c[Team Name]}} else s
        ){1}
    ),
    #"Expanded Team Name" = Table.ExpandListColumn(Matchup, "Team Name")
in
    #"Expanded Team Name"