First... will your function work non-inline with static declarations?
Code:
int MyPredefinedValues(int x)
{ static int x; // keep even out of scope
static int y;
// do something impressive here
reutrn y; }
Inlining the function would duplicate your tables, one copy for each time it's imbedded.
Performance wise there's not a lot to gain by inlining with optimizing compilers so it's not like you can double your speed or anything like that.
Generally it's bad ju-ju to put code in .h files... the compiler doesn't care but it effectively hides the code from anyone not expecting it.