In an article, Rabbi Gil Student writes that, on Shabbat:
The Mishnah Berurah (340:17) and other authorities ... permit eating cake with letters. However, they do not permit cutting letters on cake. Similarly, they forbid cutting through letters on a wrapper or piece of paper (e.g. Shemiras Shabbos Ke-Hilkhasah 9:12; R. Gersion Appel, Concise Code of Jewish Law, vol. 2, p. 199).
To peel a hard-boiled egg, I usually follow these steps:
- Crack it.
Roll it on the table. (Some say that this helps to detach the membrane from the egg white. A column by the Life Hack Investigator says that the rolling technique is almost as good as the shake method. Both of the aforementioned techniques are more popular than the spoon method.)
Remove the peel.
Where I live, many eggs have the best-before date printed on the shell. After boiling, the date marking fades but doesn't fully disappear.
Cracking and rolling the egg might be likely to tear the letters.
I'd rather not peel the egg before Shabbat and store it in a plastic bag. I bet the egg might stay fresh for more days if I keep it in its shell.
Is it okay to crack and roll a boiled egg on Shabbat, even if the rolling will tear the letters printed on the egg?
Why I think it might be okay
Maybe the final Halachic ruling is more lenient than we thought; please see Rabbi Student's full article.
Also, maybe cracking and rolling isn't guaranteed to tear the letters; so maybe this changes things. But I currently don't have any boiled eggs handy in order to experiment with and find out.
Finally, rolling an egg on a table isn't the usual way of erasing letters, so maybe the problem is reduced or eliminated.
Instead of trusting the answers here, it's best to ask your own rabbi, for many reasons.