Are every one of tabs 2-7 for specific language? I.e. you removed all references to specific 3 languages? When this is the case, then:
In table on sheet Tab1, add (temporarily) 2 additional columns. Into one of them insert a formula, which checks the table on Tab4 containing a current value of Language4 column in Tab1, and returnig some value (e.g. TRUE or FALSE) depending the result. And into another one the formula, doing likely check for current value of Language7 in Tab1 and Tab7.

Now you can set Autofilter for Tab1 to be both of those added columns indicating the match was not found (e.g. both columns have FALSE in them). Filtered rows are the unused ones.

If each of Tab2-Tab7 did have links to several language columns in Tab1 (i.e. the division between them was not based on language), then there in not enough info in your post, to decide how to filter the unused rows.