After swallowing several capsules which you thought were pain relievers, you're told that you were given "foam animal in a capsule" capsules as a joke. The foam animals expand to twenty times their original size, causing a major intestinal obstruction. Unable to pass solid waste, you die from self-toxification.
An ill-tempered waiter, dissatisfied with your gratuity, beats you to death with a pepper mill.
Well chances are that it's more likely to be along the lines of me repeatedly stabbing them with the fish knife because I'm sick of how long it's taken them to bring my meal, while everyone else is on dessert. <grumble, grumble 'sodding Italian restaurant!'>
Alternatively using initials
You die from complications of a ruptured appendix.
Which is pretty boring really Was really hoping for something involving a blaze of glory.
While driving, you fail to immediately pull over for speeding when signalled by the cop car behind you. While stopped, you attempt to open your glove compartment, and the rookie cop nervously opens fire on you. You are struck several times and die on the scene.