Their is only one reason, because God told them to
That depends on what Jewish school of thought you chose to follow.
It depends if they follow Jewish religion or Vampire religion
Snails are not kosher, so Jews who follow the rules of kashrut do not eat snails. However, not all Jews keep kosher, so some Jews do eat snails.
This makes no sense. Some kosher what?
Land animals are only Kosher if the have split hooves and chew their cud. The exception being certain types of grasshoppers that may be Kosher. Sea animals are only Kosher of they have fins and scales. Frogs don't qualify as Kosher animals. === ===
It's considered not kosher to eat meat and dairy together.
I just follow Sabbath and Hannukah and like Kosher.... Just because Jesus did it and he's my role model.... So what religion am I? Someone told me Seven-Day Adventist
There is no such thing as "Hanukkah people". Hanukkah is a Jewish holiday celebrated by Jewish people. The holiday of hanukkah doesn't add any food restrictions, other than what Jews already follow. Parmesan dip and chips are okay, but if it's a kosher household, the food must be kosher.
Kosher is anything that, under Jewish Law, is permitted. For food to be kosher, it must follow a strict set of rules governing what it contains, how it is stored, and how it is prepared among other things. So to answer your question, no.
Jewish people keep kosher. They do not eat pork or animal that were killed for meat painfully and slowly (rather then quickly,) they don't eat shellfish, and they don't eat dairy and meat together.
To be Jewish you have to accept the word of God (the Torah (aka the Old Testament)), follow the 10 commandments and become circumcised. The level of bservance after that is dependant on the person. Some choose to be orthodox and will follow the other 210+ commandments found in Leviticus, specifically the rules on Kosher eating, but this is not mandatory to be considered Jewish.
A practicing Jew (someone who observes the Jewish faith, rather than someone born to a Jewish mother) will only eat kosher food. What is and isn't kosher also changes depending on the time of year (for example, wheat products such as bread and beer are not kosher during Passover). Kosher rules can be very complex, and depending on their tradition someone may follow a few, some or all of them. Someone who wishes to eat kosher as part of their Jewish identity will likely not live as strictly as an orthodox Jew. For example, someone may avoid eating pork and shellfish (both non-kosher foods) but will not worry about mixing meat and milk products in a single dish (which would rule out, for example, any pizza with a meat topping).