Can you get multiple travel vaccines at once?

Yes, you can. You can get multiple vaccines at one--both for travel or otherwise. If you get the oral typhoid vaccine, however, you shouldn't take antibiotics at the same time...Antibiotics could kill the weakened, live bacteria in the oral vaccine before they have a chance to stimulate your immune system to make antibodies against typhoid.
Yes. In general, it is perfectly safe to get multiple vaccines (travel or otherwise) at the same time. If live-virus vaccines are given (eg: varicella, measles, yellow fever, herpes zoster), they should be given at the same time or at least four weeks apart to develop good immunity. Travel well!
Yes. Getting multiple vaccines at the same time is safe and convenient. You body is more than capable of responding to many vaccines in the same day. They are designed to stimulate your body's immune system in a way that it will 'remember' and protect you should you be exposed to the disease(s). A common cold (URI) is far more complex to your immune system than multiple vaccines on the same day.