I get elevated heart rate after eating (mostly if I eat junk food).
I got an EKG done during an event and it was ordinary sinus tachycardia. Be aware that your heart rate is supposed to increase after meals, especially large ones. Your metabolism increases, and blood is running to your stomach. A little mental focus on this - and the "problem" increases even more. If you eat a lot of sugar, your blood sugar levels can change too, which in some people causes tachycardia (elevated heart rate).
Just make sure to check your thyroid levels when you have this problem.
Quit smoking and start to exercise, though. Don't they all tell you that? ;)
A HR of 110 for short periods of time should not be dangerous. It sounds like you have had a complete series of tests and the good news is nothing is structurally wrong.
You mention a monitor and EKG, did any of that catch a high (110) HR period? It not, then you may need a longer term monitor.
Given your other symptoms I'd believe something is wrong - and it may be "electrical". The only way I know of to fully diagnose is to have a monitor/recorder on when the evens occur.
In the mean time consider quitting smoking and avoid caffeine (coffee, tea, chocolate, most dark soda, other) and see what happens. If you can't do all these things, start with the removal of caffeine from your diet.