Injector sizing

If my engine desired injector size is 300cc, can l install 1000cc injector, is too big? Does it affect value of VE table?

Well, you can install any size injectors you want but the question is do you really want to. It should come from your car goal - what do you want to get from it. Changing the injectors for a sake of changing them is not the best idea although you can still do it. But if you want to achieve substantially more power than it is different ball game. However your injector sizing should correspond to the power level you want to get - if you can achieve your goal with 750cc injectors I would not go with 1000cc injectors unless it is absolutely necessary. The reason being is that the bigger the injectors are the more non-linear the behave at low engine speed which might result in poor idle quality. So as I already said the best thing is to match the injector size with power level demand.

As for VE table - no, you will not need to recalibrate them providing that it is correct and new injectors characteristics are introduced correctly (injector size, dead time, injector base latency) in the software.