Are blessed secular objects categorically lower than or different from traditional sacramentals like altars, priest vestments, etc.? Every Thursday in the National Shrine of St. Jude Thaddeus Manila, students of various universities nearby go to Mass. After Mass, the priest comes out with his holy water and sprinkles it on the mass-goers. Students would then break out their notebooks, their pens, their pencils, their laptops, etc., and hold it up high so it would catch some holy water.

The students do this at least once in a semester during their exam periods, before defending their papers, etc., believing that when they use these now-blessed objects during review, exam, or thesis defense, they would have God's Grace (not necessarily have good luck) when they attempt to pass their academic requirements.

Take note that they are having the priest bless objects that are secular, that had been used for secular purposes, and that will be used for secular purposes.

Assuming that this method does bless their school stuff, are these categorically lower than the "normal" blessed sacramentals, such as chalices, priest vestments, and rosaries?

I am asking for the Church dogma/doctrine standpoint, please, if it applies. Thanks!
The ritual the O.P. is describing is a typical blessing of ordinary objects, of which there are many examples in the Shorter Roman Ritual, for example. (Keep in mind that there is no set “rite” for blessings of this kind—the ritual is indicative, not binding.)

The blessing of a “normal” object does not turn it into a sacramental or (better said) a sacred object. Only an object destined to specifically religious use becomes a sacred object. (I am not aware of any specific Church law regarding this, but this is clearly how the rites of blessings treat such objects.)

Such a blessing (i.e., of school supplies) is not really intended to increase one’s chances of passing an exam (I am afraid that there is no substitute for studying), but rather reflects the fact that even “mundane” goods such as these are, ultimately, given to us by God. It is a way of giving thanks to Him, and of placing potentially difficult circumstances (e.g., exams) into His hands.