[Rainrider]

local t = {
  Magic = "M",
  ["Poison"] = "P",
}
 
local dispel = "Magic"
 
print(t.Magic)
print(t["Magic"])
print(t[dispel])
 
dispel = "Poison"
 
print(t.Poison)
print(t["Poison"])
print(t[dispel])

The output is:

M
M
M
P
P
P

t.Magic is just syntactic sugar for t["Magic"]. Beware t[dispel] - it is not the same as t["dispel"] - without the quotation marks it is the variable dispel, that contains the string value "Magic", with the quotation marks it is a string literal and thus a key named "dispel" will be looked up (which does not exist in the example)

local t = { "Curse" = "C" } -- INVALID SYNTAX