How you do deal with keeping Kosher while working at a secular company? It's easy enough to bring my own lunch everyday; what I'm not sure how to handle are events like company lunches and other social activities. Bonding with co-workers over food is a common practice. I don't want to be rude or lose those opportunities.
- A buffet-style standing meal, or wine-and-cheese mixer, or the like, in the office: Just don't eat. No one will notice, or, if anyone does, you can explain why you're not eating. (Presumably, if you work there for more than a short while, someone will eventually cotton on to the fact that you keep kosher anyway.) (Note: I don't see why it'd be impermissible to attend and not eat, but CYLOR.)
- A meal in a restaurant, in someone's home, or in the office outside of working hours: As citelao's answer suggested, try and get them to hold it in a kosher restaurant or with kosher food. (I once attended a dinner held in my thesis advisor's home, and she very kindly ordered all the food (for everyone) from a kosher place and waited until I arrived to open it.) Otherwise, decline; if your absence would be weird, explain why. If you really need to attend, see the next item.
- A sit-down meal in the office during working hours: This is more difficult, as its harder to absent yourself; fortunately, it's also a lot rarer. I can see a few possibilities here, but none of them is very good. One, CYLOR about permissibility, attend if it's permissible, and don't eat. (Toy with a cup of cold water the whole time.) If anyone asks why, explain. Two, bring food. Again, explain why if asked. I only had to attend one of these, and the food was plated (not buffet style); the host very thoughtfully ordered from a kosher restaurant food to match as closely as possible the non-kosher food everyone else was eating; it came wrapped appropriately, and I tucked in with the disposable cutlery provided for me. But you can't expect that.
Having worked at a large University, and a consulting firm, I have yet to have any real issues. If you ask in advance, it is usually possible to get kosher food.
It feels a bit odd, since it comes wrapped and looks different, but it is not that bad really.
I have yet to find an instance where people give me a hard time about it. I am also big, bright, and stick out with a big kippah.
If they won't provide, I bring my own. Restaraunts, if you have enough people won't care if you bring in food. If you are with a party of 3 and try to bring your own food they may complain.
I have been to dozens (if not a hundred, I lost track) of such events with no issues.
It depends on what degree you keep Kosher.
I, for one, will not eat meat outside the house but am fine with salads and fish, etc. If that's the case, just eat something light and enjoy your time with people, eat later.
If you keep completely Kosher, perhaps you could suggest a Kosher restaurant to meet at. At that point, if they refuse to make do, it's them being rude, not you.
Company lunches seem difficult. I would eat at home first and just drink soda or something there. If anyone asks why you aren't eating, just say you already ate.
I may not be the best source because I don't work in an office, but good luck!