Which language has the largest consonant cluster inventory? Or what is a plausible, maximal consonant cluster inventory?That would be !Xoon.
ǃXóõ (or however it's supposed to be spelt) is (one of?) the languages with the biggest consonant
As for consonant clusters
, that depends what you mean.
Bella Coola famously has long grammatical complete sentences with many consonants and no vowels.
If you want "biggest consonant cluster in a word", I don't know, but I bet it's either one of those above or one of those mentioned below.
If you want "biggest consonant cluster in a syllable", it's probably a European language; English and German are both good candidates. One allows 4-consonant onsets and 3-consonant codas; the other allows 3-consonant onsets and 4-consonant coda*
clusters. Technically, I suppose, they both allow 7-consonant clusters in a word (but a syllable boundary has to occur within such a long consonant cluster).
Edit: *I left the word "coda" out.
Nobody speaks of "consonant cluster inventories". There are inventories of consonant phonemes; and there are clusters of consonant phonemes. People talk about those, but not about inventories of clusters of phonemes.
IMO the longest plausible syllable-onset-cluster and the longest plausible syllable-coda-cluster are both 4 consonants long; and IMO the longest plausible consonant cluster in a word is 7 consonants long. But, I believe some conlangers think 5-consonant onset-clusters and 5-consonant coda-clusters are (maybe only barely?) plausible; and if a 'lang had both, it could conceivably have 10-consonant clusters inside a word.
You should know, though, that 3-or-more-consonant onset-clusters and 3-or-more-consonant coda-clusters both co-occurring in the same language is a distinctly minority phenomenon; there are few such natlangs.