Yes, you absolutely can. I do it frequently, and to be honest I think it is MUCH easier for a non-professional to temper chocolate in a bowl vs. using a slab. The slab can bring a large amount of chocolate down in temperature quickly, but that is only 1 part of tempering; you also need to agitate the chocolate enough so the correct crystals form. It is very easy using a slab to cool the chocolate too quickly and have it drop too much temperature to quickly to catch and your whole batch can then go out of temper.
Easiest way is to ensure you have a good thermometer on hand (quick read digital is what I use, but you can use a bulb thermometer).
Dark, Milk, and White all temper at different temperatures, so check the internet for your correct temperature for the type of chocolate you are using.
If you let me know the type of chocolate you are going to use I can give some pointers; easiest is to buy a couple lbs of couverture chocolate in pistols (they look like flat hershey chocolate kisses, sort of). These are pre-tempered and so you chop them into 1/4's, melt to the correct temp depending on the type of chocolate, over barely simmering water, then mixing frequently/constantly you take off the heat and bring down to the "lower temperature" - this can take some time, usually about 20 mins, and if you are using a metal bowl for the chocolate you can set it on something to help draw out some of the heat (a cold counter top, etc.) but NOT ice or anything like. As you are mixing, mixing, mixing, and the chocolate is cooling it will get to your lower target temperature and by this time the correct type of crystals have formed and you can then bring it back to to the "holding temperature" by setting for a few seconds at a time over the pot of simmering water.
If using pre-tempered chocolate, you can also reserve some (about 1/8 of the total amount you are melting, give or take) and after you melt the chocolate and take if off the heat and are mixing, you introduce this unmelted, but tempered chocolate. It already has the correct type of crystals formed and so will help to get the party started in your melted batch, and it will also help to draw down the temperature a bit. I've read some books say to reserve up to 1/4 to 1/3 of you total chocolate and add it after the rest has melted, but in my experience you end up with bits of unmelted chocolate and it cools your batch too much and too quickly.
I think maybe if you are doing larger batches of chocolate (over 2 lbs) then the larger overall mass is more forgiving and has the ability to melt more added chocolate, but I generally am not melting more than 1lb at a time and so I "seed" my melted chocolate with about 10 chopped up pistols, and let elbow-grease and patience do the rest.
Of course, just dip a spoon or knift into the chocolate to test for temper.. it should harden and not be sticky in 2 minutes or so.. and should have a good solid even look, without streaks.
To keep your chocolate at the "working temperature", use a heating pad with a towel layed on top, but you'll need to check and watch your temperature until you get used to how high to have the pad set (usually pretty low.. the chocolate holds its temp pretty good), but obviously room temperature and chocolate volume will play a part. If it drops too much in temp you may need to give it a few seconds on the simmering water, and remember always mixing, mixing, mixing and keep the bowl sides as scraped down and clean as possible. As you start to dip and use the chocolate then you'll get some hard bits on the bowl sides... just leave those to build up since if you try to knock them back into the melted chocolate they can take your batch out of temper.