Well, you need use the brain and understand a bit of logic.
A list will be ever a list.
The function "append to the end of the file" work only if you use a new line as default list separator. If you use a specific char, the option bind to file will not work.
As well lists are simple structures.
Tables are complex structures.
The option append to the file will require the lists have the same structure, but this structure are dinamic.
Imagine you have a table with 2 columns and try to append to the file another structure with 4 or 10 columns.
You can say "but I'll ever use 2 columns" but you must to know, this is your situation, to solve your problem you must to use your brain (as I said in begin of post, you must use it!).