Ok, you need to choose the right size for your tablecloth and you don’t know where to start.
No panic.
Just measure your table and add a drop of 20 to 30 cm on each side.

An example?
For a table measuring 140×80 cm, you’ll need a tablecloth of at least 180×120 cm, but you can easily go up to a 200×140 cm tablecloth.

Remember, the ideal size also depends on the setting: for everyday use, just a few centimeters of drop are enough, while for a more formal and elegant table setting, you can choose a more generous drop (without overdoing it!).