How to have custom names instead of numbers for routing tables

Issue

If some custom routing table is specified via the ip command, only number for this table is possible to put down to the ip command itself as the table ID.

Use of routing table number as ID:

# ip r add default via  xxx.xxx.xxx.xxx dev ethX table 10
# ip r show table 10
default via xxx.xxx.xxx.xxx dev ethX

Use of routing table string as ID:

# ip r add default via  xxx.xxx.xxx.xxx dev ethX table my_table
Error: argument "my_table" is wrong: "table" value is invalid