POWERBI TRANSFORM TABLE TO AN OTHER

Hi,
it seems that what you want to achieve is basically a cross join parameter table. As in merge there's no cross join the way to achieve this is using a custom column referencing the second table as you can see here:
Cross join - Power Query | Microsoft Learn
Now in your case what you can do to achieve a similar scenario is to create a parameter, for instance maxInt.
Then add a blank query choose your favorite name for instance MyParameterTable and use this M language snippet

let
     MyParameterQuery = (MaxInt) => List.Numbers(1,MaxInt)
in
     MyParameterQuery

Invoking the function providing parameter value will create the list of value that you need. Default name is Invoked function but you can rename as you prefer. Once you're done with this you can rely on custom column and then expand rows as in following snippet. 

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUXIBYnelWJ1oJScgyxWIPcA8ZyDLDYg9lWJjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Col1 = _t, Col2 = _t, Col3 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Col1", type text}, {"Col2", type text}, {"Col3", type text}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each #"Invoked Function"),
    #"Renamed Columns" = Table.RenameColumns(#"Added Custom",{{"Custom", "Param"}}),
    #"Expanded Param" = Table.ExpandListColumn(#"Renamed Columns", "Param")
in
    #"Expanded Param"

Hope it helped!