Could someone please explain why we have this on the periodic table?

Good. That explains why He is 1s'2 (a duplet inert gas in group .
You know the periodic table is in blocks (s, p, d and f) based on where the valence electron lies. Helium has its valence electron in s-subshell but it lies in p-block. Why?

Helium belong 2 d p orbital because 1electron will b place in d s orbital nd d other on d p orbital b4 pairing cn occur 4rm hund's rule.i.e remember helium cn either b place in group 2 (in d s orbital) or group 8(d p orbital)

Helium is a p-block element because it is a non-metal. All non-metals (group3- are p-block elements. All metals(group1&2) are s-block elements. All transition metals are d-block elements hence they all have special characteristics. The lactinide and actinide series are f-block elements. That's what i leaned in my chemistry class.

Helium has no fixed position like hydrogen. It was placed in group viiiA in the P.T for convenience.  It can be place based on the property we are considering. It has the properties of noble gas(its duplet shell is completely filled) base on this it can be place in group viiiA .Also base on the electrons in its outermost shell it can be place in group iiA . But it is a non metal it is better to be place it in the said position to avoid confusion.

[Bejay1]
That's a point.
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[Guldberg]
Thanks. But you may have to learn more on Hund's rule.

[Bejay1]
That's a point.
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[Guldberg]
Thanks. But you may have to learn more on Hund's rule.