ah, ok. As you may have guessed, I am a scientist!
Sodium does readily form sodium chloride and other compounds, so there is a good chance that it could actually be as NaCl in your tablets.
So say you only want to consume 5g of salt per day, that is the same as consuming 2g of sodium. Either way your tablets are between 1/4 and 1/5 of this. So they may affect your blood pressure if they are increasing your sodium levels above the norm, but as you already watch your sodium/salt in take you should be ok. Most medications warn about sodium levels now and that they may effect blood pressure etc. Sodium is also vital for many bodily functions, so as long as you stay within the healthy limits, you'll be fine.
Also remember if you get dehydrated, you effectively increase your salt levels, so I would make sure you always drink enough fluid. Gentle exercise and watching your intake of saturated fat can also help blood pressure.
If you are worried, I think you could probably have a quick phone conversation with your doctor, rather than take up an appointment. Or perhaps NHS direct could advise you.
Hope this helps, sadly I'm not a doctor (well actually I am, but of the PhD variety not the medical! It's a recent thing, so keep fogetting!), but being aware of your salt intake and the fact you need to keep control of your blood pressure is definitely half the battle.