Tissue paper can't book you your seat.

No sir, no madam. I have never endorsed the idea of reserving a spot by placing something there. Either you wait, or don't bother. Get a colleague to wait while you place your order. Nobody said you have to all go at once.

So you're eating alone and the place is crowded, you find yourself a rare seat? Go ahead, I'm not saying you can't sit in it. It's public property and everyone has as equal a claim to it as the next guy. But then you want to go get food. It's just too bad that you are alone.

What does it mean by placing a packet of tissue paper on the table or seat? Perhaps to the typical (and I use typical ever so freely) Singaporean it is a sign of "this is my seat, back off! I've got a huge ass packet of tissue paper and I'm not afraid to use it!" But how would someone from another country, another culture, react to something like that?
"Oh, the previous person must have left it here."
"Oh, the previous person's a litterbug."
"how sweet, a free packet of tissue paper!"
Will it ever cross their minds that it meant the seat has been reserved? Definitely not! And deservedly so, because them typical Singaporeans have been taking that damn gesture for granted.

And do you know why foreigners simply don't get that? It's because a pack of tissue paper simply has no value. There is no ownership. "Whose is this?" Will the packet of tissue paper answer? No! It's cheap, it's doesn't belong to anyone, maybe it can be mine now.

Next time, why not leave something with more face value. Leave your Identity Card, your driving license, etc. So people might know which sanctimonious asshole is trying to book a spot.

Seriously, do Singapore a favour.