I have been to Malta about 20 years ago - so my information and experience regarding tourist masses aren't exactly up to date.
But it is a lovely little country. I was particularly enarmored with how different each of those three Maltese islands looks. While Comino is essentially a large rock, Gozo is all green and lush, while the main island, Malta, is "sandy" and "cave-y" and boasts with gorgeous architecture. We went in August and were lucky enough to witness the annual mule and donkey race in Victoria (capital of Gozo) - probably the single most memorable event of any of my vacations. Malta also offers an interesting and (I believe) unique mix of Western and Arabian influences. Think Sicily with a Moroccan edge. For instance, Malta probably has the highest Catholic population of all of Europe (maybe with the exception of the Vatican...
), but all those Maltese Catholics refer to God as "Allah". I thought that was amazing.
But the whole trip was amazing. Malta offers so much lively and vibrant diversity that I didn't quite expect from a place that tiny.
Oh, and as for spiders: In two weeks (in August) we didn't encounter a single bug, mosquito, spider or any other insect. The main island, Malta, does not have any natural fresh water sources (there's no creek, lake, or river on the island), so I guess the place isn't exactly interesting for insects. Gozo might be different, as it has natural fresh water, but since we stayed at a hotel on Malta and only took day trips to Gozo, I can't really say how bad the bug situation might get there.
Overall, Malta is a wonderful place, and I would love to go again. A friend of mine just wrapped up a three-day gig in Valetta, and he absolutely loved it. I am sure you would enjoy a trip to Malta if spiders are your only concern.