Is it 4 separate 500gm plastic bottles for the "Pack of 4"?

Yes thats right. You get 4 seprate jars of horlicks.many thanks for your inquiry.

As a kid Horlick made malt tablets. Are the tablets still made?

Yes. I believe I bought some on Amazon. My recollection is that they came from Hong Kong or maybe India. I don't kn what the original tablets were like, but these were quite hard and not to my liking. Most likely some company acquired the rights but I have no way of knowing if these are like the original formula. Interesting side bit. I heard abut Horlicks Malt from listing to old Lum and Abner radio shows fro the 1930s. An ad that was still effective almost 100 years later.