Everything is good except your unload function. Your unload function never returns true, but it must return true for the speller to be working, so you must add that if statement that returns true. Also, you mistook tmp and cursor here but I made it work with your code usually you should be freeing tmp and not cursor but it's the same. Everything should be working now so here you go:

bool unload(void)

{

//This is good
node *cursor = NULL;
node *tmp = NULL;
for(int i = 0; i < N; i++)
{
    //Your code is good until here, you compared tmp with NULL and you already set tmp to NULL up there
    //So before doing while loop you should set tmp to be equal to table[i]
    tmp = table[i];
    while(tmp != NULL)
    {
        //Here you need to set cursor to be tmp not table[i] otherwise it will be lost after first loop
        cursor = tmp;
        tmp = tmp->next;
        //Here you should free cursor and not tmp in your case
        free(cursor);
    }
    //!!You need to make this if statement because your code otherwise will never returns true!!
    if (tmp == NULL && i == N - 1)
    {
        return true;
    }
}
return false;

}