I am currently working on one, and I wonder if there are any other .net libraries with table functions?

With "table function" I mean functions with tables as input and output parameters like:

T3 = f(T1, T2), where T1, T2 and T3 are tables.

The distribution function often used in accounting or financial planning is for example a typical table function.

For example, distribution of costs per department to teams.

DistributedCostTable = DistributionFunc(CostTable, KeyTable)

CostTable = costs(department, year)
KeyTable = DitsributionRatio(department, team)

DistributionFunc is here a table function, with tables as input and output parameters.

Business planning tools like SAP's offer such standard table functions like Allocations/Distributions. SAP FOX formulas are also table functions with user-defined formulas.