Dwarves have advantage to saving throws against poison, +2 con, and resistance to poison damage. If your a hill dwarf you even gain +1 HP per level. So a Dwarven commoner would have 6 whole HP compared to a human's 4.
A common vial of poison deals 1d4 damage on a failed dc 10 con save. A human commoner would have a 45% chance of failing this and an 11.25% chance of dying outright. Meanwhile a dwarf commoner would only have a 16% chance of failing the save and will certainly survive it as long as they're in good health. In fact, between the odds of succeeding the save, and the odds of rolling one damage which gets rounded down from resistance, there's an 88% of a dwarf drinking a vial plof poison to suffer no effects whatsoever.
A dwarf could easily drink a vial of poison at each meal and mathematically still be fine. Even in the worst case scenario where they fail and take 2 damage each sip, they can still short rest to gain 1d8+2 hp back. And this dire scenario would only happen 1 in two million days.
Considering that humans regularly eat poisons for enjoyment like capsaicin, caffeine, or THC, I wouldn't be surprised if a dwarves could dump poison into their meals just because they like how it tastes. Sure it occasionally results in some indigestion pains, but don't be a baby about it. It's fine. At least it is until your human friends collapse dead at the dinner table.