I take about 10 grams or more a day mixed into my protein shakes when I work out. That would be 20 or more of your tablets. Others who have a more serious workout program tell me thay take much more, over 20 grams. So, rather than questioning if 3 500 mg tablets (1.5 grams) is too much, I wonder if it is enough to do anything at all. I buy it as a powder, not tablets. The directions on one brand of the powder indicate a standard dose is two scoops = 9 grams, and that this dose might be taken with each protein supplement drink, i.e. several times per day.
By the way, buying L-Arginine in tablet form is a waste of money, unless you really want the conveneince of the tablets. It is much cheaper when purchased as a bulk powder. You can buy the powder at GNC stores for about a third of the cost of their tablets (by weight), but if you go to a good independent fitness store, the powder is costs even less. The powder can be dissolved in a drink, and has little taste, although there is a very slight impression of something like ammonia. Some of the more expensive brands add a little citric acid to give a pleasant citrus taste, but you get used to the plain version soon enough.