Why is the ionic radius of hydride so large?
It is not.
Presenting the order of ionic radii like that is useless.
Ionic radius of a given ion is not constant and mainly rely on crystal structure (coordination environment, more precisely) and used experimental techniques (crystal structure determination and theoretical calculations).
As a consequence, you can only compare homogeneous data.
Proposing the ordering based on some cherry-picked values from random sources or their averaged values is pointless at best.
This very issue is discussed by Messer [1]:

The effective ionic radius of fluoride ion is given as 1.33 Å by Pauling (8) and 1.36 Å, by Zachariasen (9), for coordination number 6. The effective ionic radius of hydride ion varies from 1.27 to 1.52 Å (10), being much more highly sensitive to the particular cation present and to the particular assumptions used in deriving the radius than the fluoride value. For the alkali metal hydrides other than lithium hydride, with the same face-centered cubic structure as the corresponding fluorides, the effective hydride radius is 1.47 Å for $\ce{Na+},$ and 1.52–1.54 Å for $\ce{K+},$ $\ce{Rb+},$ and $\ce{Cs+}.$ For $\ce{LiH},$ $\ce{CaH},$ and $\ce{BaH},$ the hydride ion radius is 1.34–1.36 Å. The closest similarities between hydrides and fluorides should thus appear here.

You can find the order of ionic radii for group 1 hydrides and halides in a more recent work by Lang and Smith [2]:

$$\ce{Li+} &lt; \ce{H-} &lt; \ce{Na+} &lt; \ce{F-} &lt; \ce{K+} &lt; \ce{Cl-} &lt; \ce{Rb+} &lt; \ce{Br-} &lt; \ce{Cs+} &lt; \ce{I-}$$

Again, note that this doesn't only contradict your order, but it is no universal sequence and is only true for these compounds with soft-sphere model used for calculation.
References

Messer, C. E. Hydrides versus Fluorides: Structural Comparisons. Journal of Solid State Chemistry 1970, 2 (2), 144–155. DOI: 10.1016/0022-4596(70)90062-9.
Lang, P. F.; Smith, B. C. Ionic Radii for Group 1 and Group 2 Halide, Hydride, Fluoride, Oxide, Sulfide, Selenide and Telluride Crystals. Dalton Trans. 2010, 39 (33), 7786. DOI: 10.1039/c0dt00401d.